session-name: Specify a static BFD session by its name, a case-sensitive string of 1 to 64 characters. The specified static BFD session cannot be the current static BFD session.

re-negotiate seconds: Specifies the maximum amount of time that the associated static BFD session can perform negotiation. The value range for the seconds argument is 10 to 600 seconds. The default is 60 seconds. This option takes effect only on bidirectional associations.

Usage guidelines

The device supports the following association types for two static BFD sessions (static BFD session a and static BFD session b are used for illustration):

· Unidirectional association—Session a is associated with session b in the view of session a, or session b is associated with session a in the view of session b.

· Bidirectional association—Session a is associated with session b in the view of session a, and session b is associated with session a in the view of session b.

A unidirectional association works as follows (the association configured in the view of static BFD session a is taken as an example):

1. When session a changes to the Down state, session b also changes to the Down state. Before session a comes up, session b is not allowed to perform negotiation.

2. When session a changes to the Up state, static BFD session b starts to perform negotiation. The state of session a is not affected even if session b cannot come up through negotiation.

A bidirectional association works as follows:

1. When session a changes to the Down state, session b also changes to the Down state. Before session a comes up, session b is not allowed to perform negotiation.

2. When session a changes to the Up state, session b starts to perform negotiation.

¡ If session b comes up through negotiation in the specified time, both static BFD sessions are placed in Up state.

¡ If session b fail to come up through negotiation in the specified time, both static BFD sessions are placed in Down state.

3. The same rules apply to the state changes of session a if session b first changes to the Down state.

To change an associated static BFD session, first execute the undo associate-static-session command and then associate a new static BFD session by using the associate-static-session command.

Examples

# Associate static BFD session aaa with static BFD session bbb.

<Sysname> system-view

[Sys name] bfd static aaa

[Sysname-bfd-static-session-aaa] associate-static-session bbb

bfd authentication-mode

Use bfd authentication-mode to configure the BFD authentication mode for single-hop BFD control packets.

Use undo bfd authentication-mode to restore the default.

Syntax

bfd authentication-mode { hmac-md5 | hmac-mmd5 | hmac-msha1 | hmac-sha1 | m-md5 | m-sha1 | md5 | sha1 | simple } key-id { cipher | plain } string

undo bfd authentication-mode

Default

Single-hop BFD control packets are not authenticated.

Views

Interface view

BFD template view

Predefined user roles

network-admin

Parameters

hmac-md5: Specifies the HMAC MD5 algorithm.

hmac-mmd5: Specifies the HMAC Meticulous MD5 algorithm.

hmac-msha1: Specifies the HMAC Meticulous SHA1 algorithm.

hmac-sha1: Specifies the HMAC SHA1 algorithm.

m-md5: Specifies the Meticulous MD5 algorithm.

m-sha1: Specifies the Meticulous SHA1 algorithm.

md5: Specifies the MD5 algorithm.

sha1: Specifies the SHA1 algorithm.

simple: Specifies the simple authentication mode.

key-id: Sets the authentication key ID in the range of 1 to 255.

cipher: Specifies a key in encrypted form.

plain: Specifies a key in plaintext form. For security purposes, the key specified in plaintext form will be stored in encrypted form.

string: Specifies the key. Its plaintext form is a case-sensitive string of 1 to 16 characters. Its encrypted form is a case-sensitive string of 33 to 53 characters.

Usage guidelines

Use this command to enhance BFD session security.

BFD version 0 does not support this command. The configuration does not take effect.

A static BFD session supports this command only when it is in IPv4 or IPv6 control packet mode used for single-hop detection.

Examples

# Configure GigabitEthernet 1/0/1 to perform simple authentication for single-hop BFD control packets, setting the authentication key ID to 1 and plaintext key to 123456.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] bfd authentication-mode simple 1 plain 123456

bfd dampening

Use bfd dampening to configure BFD session flapping suppression.

Use undo bfd dampening to disable BFD session flapping suppression.

Syntax

bfd dampening [ maximum maximum-interval initial initial-interval secondary secondary-interval ]

undo bfd dampening

Default

BFD sessions are not suppressed.

Views

System view

Predefined user roles

network-admin

Parameters

maximum-interval: Specifies the maximum time a BFD session is suppressed, in the range of 1 to 3600 seconds. The default is 20 seconds.

initial-interval: Specifies the amount of time a BFD session is suppressed for the first time. The value range for the initial-interval argument is 1 to 3600 seconds. The default is 6 seconds.

secondary-interval: Specifies the amount of time a BFD session is suppressed for the second time. The value range for the secondary-interval argument is 1 to 3600 seconds. The default is 10 seconds.

Usage guidelines

When BFD detects a link failure, it tears down the BFD session and notifies the upper-layer protocol of the failure. When the upper-layer protocol re-establishes a neighbor relationship, the BFD session comes up again. BFD session flaps occur when a link fails and recovers repeatedly, which consumes significant system resources and causes network instability.

This command allows you to suppress BFD session flapping by using the initial-interval, secondary-interval, and maximum-interval arguments.

· A BFD session is suppressed within the specified interval. The suppression time does not exceed the maximum-interval.

· After a BFD session goes down for the second time, it cannot be re-established within the initial-interval.

· After a BFD session goes down for the third time, it cannot be re-established within the secondary-interval.

· After a BFD session goes down for the fourth time and at any later time, the following rules apply:

¡ If secondary-interval × 2n-3 is smaller than or equal to the maximum-interval, the BFD session cannot be re-established within the secondary-interval × 2n-3.

¡ If secondary-interval × 2n-3 is greater than the maximum-interval, the BFD session cannot be re-established within the maximum-interval.

The letter n, starting from 4, is the number of times the BFD session flaps.

Examples

# Enable BFD session flapping suppression, and set the maximum-interval, initial-interval, and secondary-interval to 12 seconds, 4 seconds, and 8 seconds, respectively.

<Sysname> system-view

[Sysname] bfd dampening maximum 12 initial 4 secondary 8

bfd demand enable

Use bfd demand enable to enable the Demand BFD session mode.

Use undo bfd demand enable to restore the default.

Syntax

bfd demand enable

undo bfd demand enable

Default

The BFD session is in Asynchronous mode.

Views

Interface view

Predefined user roles

network-admin

Usage guidelines

In Demand mode, the device periodically sends BFD control packets. If the peer end is operating in Asynchronous mode (default), the peer end stops sending BFD control packets. If the peer end is operating in Demand mode, both ends stop sending BFD control packets. When a system in Demand mode wants to verify the connectivity to another system, it sends several BFD control packets with the Poll (P) bit set at the negotiated transmit interval. If no response is received within the detection interval, the session is considered down. If the connectivity is found to be up, no more BFD control packets are sent until the next command is issued. As a best practice, configure the bfd echo enable command together with this command to detect connectivity by sending Echo packets. If the device does not receive any Echo packets from the peer end, it considers the session down.

In Asynchronous mode, the device periodically sends BFD control packets. The device considers that the session is down if it does not receive any BFD control packets within a specific interval.

BFD version 0 does not support this command. The configuration does not take effect.

Examples

# Enable the Demand BFD session mode on GigabitEthernet 1/0/1.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] bfd demand enable

Related commands

bfd echo enable

bfd detect-interface

Use bfd detect-interface source-ip to associate the interface state with BFD.

Use undo bfd detect-interface to remove the association between the interface state and BFD.

Syntax

bfd detect-interface source-ip ip-address [ discriminator local local-value remote remote-value ] [ template template-name ]

undo bfd detect-interface

Default

The interface state is not associated with BFD.

Views

Interface view

Predefined user roles

network-admin

Parameters

ip-address: Specifies the source IP address for BFD control packets.

discriminator: Specifies BFD session discriminators. If you do not specify discriminators, the device obtains BFD session discriminators through autonegotiation.

local local-value: Specifies the local discriminator. The value range for the local-value argument is 1 to 32768.

remote remote-value: Specifies the remote discriminator in the range of 1 to 4294967295.

template template-name: Specifies a template by its name, a case-sensitive string of 1 to 63 characters. If you specify a nonexistent template or do not specify a template, the BFD session uses the BFD parameters configured in interface view. If you first specify a nonexistent template and then create the template, the BFD session uses the parameters configured in the template.

Usage guidelines

By creating a BFD session for single-hop detection through exchange of BFD control packets, this feature implements fast link detection.. When BFD detects a link fault, it sets the link layer protocol state to DOWN(BFD). This behavior helps applications relying on the link layer protocol state achieve fast convergence. The source IP address of control packets is specified manually, and the destination IP address is fixed at 224.0.0.184. As a best practice, specify the IP address of the interface as the source IP address. If the interface does not have an IP address, specify a unicast IP address other than 0.0.0.0 as the source IP address.

You can associate the state of the following interfaces with BFD:

· Layer 3 Ethernet interfaces.

· Member ports in a Layer 3 aggregation group.

· Layer 3 Ethernet subinterfaces.

· Layer 3 aggregate interfaces

· Layer 3 aggregate subinterfaces

· Serial interfaces, POS interfaces, serial interfaces created from E1, E3, T1, or T3, MP-group interfaces, member interfaces of an MP-group interface, HDLC link bundle interfaces, and member interfaces of an HDLC link bundle interface.

If the link layer protocol of an interface is modified by using the link-protocol command, the association between the interface state and BFD is automatically cancelled. When associating the state of a member interface of an MP-group interface or of an HDLC link bundle interface, you must specify the discriminator parameter.

This command must be configured on both ends of the link for a BFD session to be established.

For BFD detection to take effect, do not configure this command on both a Layer 3 Ethernet interface and its subinterface.

To associate the interface state with BFD successfully and avoid session state exceptions, as a best practice, do not set demand mode for the BFD session.

If the peer device does not support obtaining BFD session discriminators through autonegotiation, you must specify the discriminators on both the local and peer devices. Without the discriminators, the BFD session cannot come up.

The BFD session discriminators must match on the local and peer devices. For example, if you configure bfd detect-interface source-ip 20.1.1.1 discriminator local 513 remote 514 on the local device, you must configure bfd detect-interface source-ip 20.1.1.1 discriminator local 514 remote 513 on the peer device.

The local discriminators of BFD sessions for interfaces on the same device must be different.

The echo function does not take effect on BFD sessions associated with interface states.

To detect data link layer connectivity for an interface, execute one of the following commands:

· bfd detect-interface source-ip

· bfd static session-name peer-ip default-ip interface interface-type interface-number source-ip ip-address

Examples

# Associate GigabitEthernet 1/0/1 with BFD to detect the interface state, and specify the source IP address for BFD control packets as 20.1.1.1.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] bfd detect-interface source-ip 20.1.1.1

Related commands

link-protocol (Interface Command Reference)

bfd static

bfd detect-interface first-fail-timer

Use bfd detect-interface first-fail-timer to configure the timer that delays reporting the first BFD session establishment failure to the data link layer.

Use undo bfd detect-interface first-fail-timer to restore the default.

Syntax

bfd detect-interface first-fail-timer seconds

undo bfd detect-interface first-fail-timer

Default

The first BFD session establishment failure is not reported to the data link layer.

Views

Interface view

Predefined user roles

network-admin

Parameters

seconds: Specifies the timeout time that reports the first BFD session establishment failure to the data link layer. The value range for this argument is 1 to 10000 seconds.

Usage guidelines

If the BFD session fails to be established when the timer expires, BFD reports the failure to the data link layer and sets the data link layer state of the interface to DOWN(BFD). This behavior rapidly identifies the interfaces for which BFD sessions fail to be established. In this case, the BFD session state is displayed as Down in the display bfd session command output. The line protocol state of the interface is displayed as DOWN(BFD) in the display interface command output.

If you execute the bfd detect-interface source-ip command on the local end, the BFD session for detecting the local interface state fails to be established when the following conditions exist:

· The bfd detect-interface source-ip command is not executed on the remote end.

· The local and remote ends have mismatching BFD authentication settings.

Examples

# Configure the timer that delays reporting the first BFD session establishment failure as 10 seconds for GigabitEthernet 1/0/1.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] bfd detect-interface first-fail-timer 10

Related commands

bfd detect-interface source-ip

display interface (Interface Command Reference)

bfd detect-interface special-processing

Use bfd detect-interface special-processing to enable special processing for BFD sessions.

Use undo bfd detect-interface special-processing to disable special processing for BFD sessions.

Syntax

bfd detect-interface special-processing [ admin-down | authentication-change | session-up ] *

undo bfd detect-interface special-processing [ admin-down | authentication-change | session-up ] *

Default

All types of special processing for BFD sessions are disabled.

Views

Interface view

Predefined user roles

network-admin

Parameters

admin-down: Notifies a session down event to the data link layer upon receipt of a BFD packet with the State field as AdminDown. This keyword helps rapidly discover interfaces on which BFD sessions are manually shut down. If you do not specify this keyword, the device sets the BFD session state to Down, but does not notify the session down event to the data link layer.

authentication-change: Immediately sets the session to down state upon a local authentication information change. This keyword helps rapidly discover interfaces with authentication information changes. If you do not specify this keyword, the device sets the session to down state if authentication information inconsistency still persists after a period of time.

session-up: Ignores authentication information inconsistency when the local session is up. If a large number of BFD sessions exist, examining authentication information consistency affects device performance. If you do not specify this keyword, the device examines authentication information in incoming BFD packets when the local session state is up. If the authentication information does not match on the two ends, the BFD session is declared down.

Usage guidelines

If you do not specify any parameters, this command enables or disables all types of special processing.

When the authentication mode for BFD packets is M-MD5, M-SHA1, HMAC-MMD5, or HMAC-MSHA1, configuring the bfd detect-interface special-processing session-up command on only the local or remote end will cause BFD session flapping. To avoid this issue, perform one of the following tasks:

· Change the authentication mode for BFD packets.

· Configure the bfd detect-interface special-processing session-up command on both of the local and remote ends.

Examples

# Enable all types of special processing for BFD sessions on GigabitEthernet 1/0/1.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] bfd detect-interface special-processing admin-down authentication-change session-up

bfd detect-multiplier

Use bfd detect-multiplier to set the single-hop detection time multiplier for control packet mode and echo packet mode.

Use undo bfd detect-multiplier to restore the default.

Syntax

bfd detect-multiplier value

undo bfd detect-multiplier

Default

The single-hop detection time multiplier is 3.

Views

Interface view

BFD template view

Predefined user roles

network-admin

Parameters

value: Specifies a detection time multiplier. The value range for this argument is 3 to 50.

Usage guidelines

The detection time multiplier determines the maximum number of concurrent BFD packets (including control packets and echo packets) that can be discarded.

Table 1 Actual detection interval calculation method

Mode	Actual detection interval of the sender
Echo packet mode	Detection time multiplier of the sender × actual packet sending interval of the sender
Control-packet-mode BFD session in asynchronous mode	Detection time multiplier of the receiver × MAX (minimum receiving interval supported by the sender, minimum sending interval supported by the receiver)
Control-packet-mode BFD session in demand mode	Detection time multiplier of the sender × MAX (minimum sending interval supported by the sender, minimum receiving interval supported by the receiver)

Only the following static BFD sessions support this command:

· Static BFD sessions in IPv4 control packet mode used for single-hop detection.

· Static BFD sessions in IPv4 echo packet mode used for single-hop detection.

· Static BFD sessions in IPv6 control packet mode used for single-hop detection.

· Static BFD sessions in IPv6 echo packet mode used for single-hop detection.

Examples

# Set the single-hop detection time multiplier for control packet mode and echo packet mode to 6 on GigabitEthernet 1/0/1.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] bfd detect-multiplier 6

bfd echo enable

Use bfd echo enable to enable the echo function.

Use undo bfd echo enable to disable the echo function.

Syntax

bfd echo [ receive | send ] enable

undo bfd echo [ receive | send ] enable

Default

The echo function is disabled.

Views

Interface view

Predefined user roles

network-admin

Parameters

receive: Specifies the echo packet receiving capability.

send: Specifies the echo packet sending capability.

Usage guidelines

If you enable the echo function for a BFD session in which control packets are sent and the session comes up, BFD performs the following operations:

· Periodically sends echo packets to detect link connectivity.

· Decreases the control packet receiving rate at the same time.

To enable only the echo packet receiving capability, use the bfd echo receive enable command.

To enable only the echo packet sending capability, use the bfd echo send enable command.

If you do not specify the receive or send keyword, the command enables both the echo packet receiving and sending capabilities.

The echo function does not take effect on BFD sessions associated with interface states.

The echo function does not take effect on BFD sessions in control packet mode that use IPv6 link-local addresses.

If you configure both the bfd detect-interface and bfd echo enable commands for an interface, only the bfd detect-interface command takes effect.

BFD version 0 does not support this command. The configuration does not take effect.

A static BFD session supports this command only when it is in IPv4 or IPv6 control packet mode used for single-hop detection.

Examples

# Enable the echo function on GigabitEthernet 1/0/1.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] bfd echo enable

bfd echo-source-ip

Use bfd echo-source-ip to configure the source IP address of BFD echo packets.

Use undo bfd echo-source-ip to remove the configured source IP address of BFD echo packets.

Syntax

bfd echo-source-ip ip-address

undo bfd echo-source-ip

Default

No source IP address is configured for BFD echo packets.

Views

System view

Predefined user roles

network-admin

Parameters

ip-address: Specifies the source IP address of BFD echo packets. The source IP address must be a valid unicast IPv4 address in dotted decimal notation.

Usage guidelines

As a best practice, execute this command only one end, and do not configure the source IP address to be on the same network segment as any local interface's IP address. If you configure such a source IP address, a large number of ICMP redirect packets might be sent from the peer, resulting in link congestion.

Examples

# Configure the source IP address of BFD echo packets as 8.8.8.8.

<Sysname> system-view

[Sysname] bfd echo-source-ip 8.8.8.8

bfd echo-source-ipv6

Use bfd echo-source-ipv6 to configure the source IPv6 address of BFD echo packets.

Use undo bfd echo-source-ipv6 to remove the configured source IPv6 address of BFD echo packets.

Syntax

bfd echo-source-ipv6 ipv6-address

undo bfd echo-source-ipv6

Default

No source IPv6 address is configured for BFD echo packets.

Views

System view

Predefined user roles

network-admin

Parameters

ipv6-address: Specifies the source IPv6 address for BFD echo packets.

Usage guidelines

The source IPv6 address of echo packets can only be a global unicast address.

As a best practice, execute this command only one end. The source IPv6 address cannot be on the same network segment as any local interface's IP address. Otherwise, a large number of ICMP redirect packets might be sent from the peer, resulting in link congestion.

Examples

# Configure the source IPv6 address of BFD echo packets as 80::2.

<Sysname> system-view

[Sysname] bfd echo-source-ipv6 80::2

bfd init-fail-timer

Use bfd init-fail-timer to set the delay timer for BFD to notify upper-layer protocols of session establishment failures.

Use undo bfd init-fail-timer to restore the default.

Syntax

bfd init-fail-timer seconds

undo bfd init-fail-timer

Default

BFD does not notify upper-layer protocols of session establishment failures.

Views

System view

Predefined user roles

network-admin

Parameters

seconds: Specifies the delay time in the range of 5 to 600 seconds. After the delay time, BFD notifies the upper-layer protocol of session establishment failures.

Usage guidelines

CAUTION:

For session establishment failures caused by configuration mismatches at the two ends, this command can cause the upper-layer protocol to act incorrectly. Therefore, use this command with caution. BFD status mismatch and BFD authentication configuration mismatch are examples of configuration mismatches.

This command takes effect only for control packet mode.

In some cases, for an upper-layer protocol to act correctly, BFD must notify the upper-layer protocol of session establishment failures. For example, with this command configured, the link aggregation module can promptly set the state of a member port from Selected to Unselected in the case of a link failure.

Examples

# Set the delay timer to 10 seconds for BFD to notify upper-layer protocols of session establishment failures.

<Sysname> system-view

[Sysname] bfd init-fail-timer 10

bfd min-echo-receive-interval

Use bfd min-echo-receive-interval to set the minimum interval for receiving BFD echo packets.

Use undo bfd min-echo-receive-interval to restore the default.

Syntax

bfd min-echo-receive-interval interval

undo bfd min-echo-receive-interval

Default

The minimum interval for receiving BFD echo packets is 1000 milliseconds.

Views

Interface view

BFD template view

Predefined user roles

network-admin

Parameters

interval: Specifies the minimum interval for receiving BFD echo packets, in milliseconds. The value takes 0 or is in the range of 10 to 10000.

Usage guidelines

This command sets the BFD echo packet receiving interval, which is the actual BFD echo packet sending interval.

The local end stops sending echo packets after autonegotiation with the remote end if the following conditions are met:

· The echo mode is enabled on the local end.

· The minimum interval for receiving BFD echo packets is set to 0 milliseconds on the remote end.

Only the following static BFD sessions support this command:

· Static BFD sessions in IPv4 control packet mode used for single-hop detection.

· Static BFD sessions in IPv4 echo packet mode used for single-hop detection.

· Static BFD sessions in IPv6 control packet mode used for single-hop detection.

· Static BFD sessions in IPv6 echo packet mode used for single-hop detection.

Examples

# Set the minimum interval for receiving BFD echo packets to 500 milliseconds on GigabitEthernet 1/0/1.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] bfd min-echo-receive-interval 500

bfd min-receive-interval

Use bfd min-receive-interval to set the minimum interval for receiving single-hop BFD control packets.

Use undo bfd min-receive-interval to restore the default.

Syntax

bfd min-receive-interval interval

undo bfd min-receive-interval

Default

The minimum interval for receiving BFD echo packets is 1000 milliseconds.

Views

Interface view

BFD template view

Predefined user roles

network-admin

Parameters

interval: Specifies the minimum interval for receiving single-hop BFD control packets, in milliseconds.

Support for this parameter depends on the MPU model. The following compatibility matrix shows the value ranges for the parameter:

MPU models	Value ranges
MSU-100	10 to 10000
MSU-200	10 to 10000
MSU-400-G	5 to 10000

‌

Usage guidelines

Use this command to prevent the control packet sending rate of the peer end from exceeding the control packet receiving rate of the local end.

The actual control packet sending interval of the peer end takes the greater value between the following values:

· Minimum interval for transmitting BFD control packets on the peer end.

· Minimum interval for receiving BFD control packets on the local end.

A static BFD session supports this command only when it is in IPv4 or IPv6 control packet mode used for single-hop detection.

Examples

# Set the minimum interval for receiving single-hop BFD control packets to 500 milliseconds on GigabitEthernet 1/0/1.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] bfd min-receive-interval 500

bfd min-transmit-interval

Use bfd min-transmit-interval to set the minimum interval for transmitting single-hop BFD control packets.

Use undo bfd min-transmit-interval to restore the default.

Syntax

bfd min-transmit-interval interval

undo bfd min-transmit-interval

Default

The minimum interval for receiving BFD echo packets is 1000 milliseconds.

Views

Interface view

BFD template view

Predefined user roles

network-admin

Parameters

interval: Specifies the minimum interval for transmitting single-hop BFD control packets, in milliseconds.

Support for this parameter depends on the MPU model. The following compatibility matrix shows the value ranges for the parameter:

MPU models	Value ranges
MSU-100	10 to 10000
MSU-200	10 to 10000
MSU-400-G	5 to 10000

‌

Usage guidelines

Use this command to prevent the BFD packet sending rate from exceeding the device capability.

The actual BFD control packet transmitting interval on the local end is the greater value between the following values:

· Minimum interval for transmitting BFD control packets on the local end.

· Minimum interval for receiving BFD control packets on the peer end.

A static BFD session supports this command only when it is in IPv4 or IPv6 control packet mode used for single-hop detection.

Examples

# Set the minimum interval for transmitting single-hop BFD control packets to 500 milliseconds on GigabitEthernet 1/0/1.

<Sysname> system-view

[Sysname] interface gigabitethernet 1/0/1

[Sysname-GigabitEthernet1/0/1] bfd min-transmit-interval 500

bfd multi-hop authentication-mode

Use bfd multi-hop authentication-mode to configure the authentication mode for multihop BFD control packets.

Use undo bfd multi-hop authentication-mode to restore the default.

Syntax

bfd multi-hop authentication-mode { hmac-md5 | hmac-mmd5 | hmac-msha1 | hmac-sha1 | m-md5 | m-sha1 | md5 | sha1 | simple } key-id { cipher | plain } string

undo bfd multi-hop authentication-mode

Default

No authentication is performed.

Views

System view

Static BFD session view

Predefined user roles

network-admin

Parameters

hmac-md5: Specifies the HMAC MD5 algorithm.

hmac-mmd5: Specifies the HMAC Meticulous MD5 algorithm.

hmac-msha1: Specifies the HMAC Meticulous SHA1 algorithm.

hmac-sha1: Specifies the HMAC SHA1 algorithm.

m-md5: Specifies the Meticulous MD5 algorithm.

m-sha1: Specifies the Meticulous SHA1 algorithm.

md5: Specifies the MD5 algorithm.

sha1: Specifies the SHA1 algorithm.

simple: Specifies the simple authentication mode.

key-id: Sets the authentication key ID in the range of 1 to 255.

cipher: Specifies a key in encrypted form.

plain: Specifies a key in plaintext form. For security purposes, the key specified in plaintext form will be stored in encrypted form.

string: Specifies the key. Its plaintext form is a case-sensitive string of 1 to 16 characters. Its encrypted form is a case-sensitive string of 33 to 53 characters.

Usage guidelines

Use this command to enhance BFD session security.

BFD version 0 does not support this command. The configuration does not take effect.

A static BFD session supports this command only when it is in IPv4 or IPv6 control packet mode used for multihop detection.

Examples

# Configure the simple authentication mode for multihop BFD control packets, setting the authentication key ID to 1 and key to 123456.

<Sysname> system-view

[Sysname] bfd multi-hop authentication-mode simple 1 plain 123456

bfd multi-hop destination-port

Use bfd multi-hop destination-port to configure the destination port number for multihop BFD control packets.

Use undo bfd multi-hop destination-port to restore the default.

Syntax

bfd multi-hop destination-port port-number

undo bfd multi-hop destination-port

Default

The destination port number for multihop BFD control packets is 4784.

Views

System view

Predefined user roles

network-admin

Parameters

port-number: Specifies the destination port number of multihop BFD control packets, 3784 or 4784.

Usage guidelines

IANA assigned port number 4784 to BFD for multihop BFD detection in control packet mode. By default, H3C devices use 4784 as the destination port number for multihop BFD control packets, while devices from other vendors might use 3784. To avoid BFD session establishment failures, make sure the devices on both ends of the BFD session use the same destination port number for multihop BFD control packets.

This command applies to only new multihop BFD sessions in control packet mode.

Examples

# Specify the destination port number for multihop BFD control packets as 3784.

<Sysname> system-view

[Sysname] bfd multi-hop destination-port 3784

bfd multi-hop detect-multiplier

Use bfd multi-hop detect-multiplier to set the multihop detection time multiplier for control packet mode and echo packet mode.

Use undo bfd multi-hop detect-multiplier to restore the default.

Syntax

bfd multi-hop detect-multiplier value

undo bfd multi-hop detect-multiplier

Default

The multihop detection time multiplier for control mode is 3.

Views

System view

Static BFD session view

Predefined user roles

network-admin

Parameters

value: Specifies the multihop detection time multiplier. The value range for this argument is 3 to 50.

Usage guidelines

The detection time multiplier determines the maximum number of concurrent BFD control packets that can be discarded.

Table 2 Actual detection interval calculation method

Mode	Actual detection interval of the sender
Control-packet-mode BFD session in asynchronous mode	Detection time multiplier of the receiver × MAX (minimum receiving interval supported by the sender, minimum sending interval supported by the receiver)
Control-packet-mode BFD session in demand mode	Detection time multiplier of the sender × MAX (minimum sending interval supported by the sender, minimum receiving interval supported by the receiver)

Only the following static BFD sessions support this command:

· Static BFD sessions in IPv4 control packet mode used for multihop detection.

· Static BFD sessions in IPv4 echo packet mode used for multihop detection.

· Static BFD sessions in IPv6 control packet mode used for multihop detection.

· Static BFD sessions in IPv6 echo packet mode used for multihop detection.

Examples

# Set the multihop detection time multiplier to 6 for control mode.

<Sysname> system-view

[Sysname] bfd multi-hop detect-multiplier 6

bfd multi-hop min-echo-receive-interval

Use bfd multi-hop min-echo-receive-interval to set the minimum interval for receiving multihop BFD echo packets.

Use undo bfd multi-hop min-echo-receive-interval to restore the default.

Syntax

bfd multi-hop min-echo-receive-interval interval

undo bfd multi-hop min-echo-receive-interval

Default

The minimum interval for receiving multihop BFD echo packets is 1000 milliseconds.

Views

System view

Predefined user roles

network-admin

Parameters

interval: Specifies the minimum interval for receiving multihop BFD echo packets, in milliseconds. The value takes 0 or is in the range of 10 to 10000.

Usage guidelines

The interval for receiving multihop BFD echo packets is also the interval for sending multihop BFD echo packets. By executing this command, you can control both the receiving interval and sending interval for multihop BFD echo packets.

A static BFD session supports this command only when it is in IPv4 or IPv6 echo packet mode used for multihop detection.

Examples

# Set the minimum interval for receiving multihop BFD echo packets to 500 milliseconds.

<Sysname> system-view

[Sysname] bfd multi-hop min-echo-receive-interval 500

Related commands

bfd static

bfd multi-hop min-receive-interval

Use bfd multi-hop min-receive-interval to set the minimum interval for receiving multihop BFD control packets.

Use undo bfd multi-hop min-receive-interval to restore the default.

Syntax

bfd multi-hop min-receive-interval interval

undo bfd multi-hop min-receive-interval

Default

The minimum interval for receiving multihop BFD control packets is 1000 milliseconds.

Views

System view

Static BFD session view

Predefined user roles

network-admin

Parameters

interval: Specifies the minimum interval for receiving multihop BFD control packets, in milliseconds.

Support for this parameter depends on the MPU model. The following compatibility matrix shows the value ranges for the parameter:

MPU models	Value ranges
MSU-100	10 to 10000
MSU-200	10 to 10000
MSU-400-G	5 to 10000

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Usage guidelines

Use this command to prevent the packet sending rate of the peer end from exceeding the packet receiving capability (minimum control packet receiving interval) of the local end. If the receiving capability is exceeded, the peer end dynamically adjusts the BFD control packet sending interval to the minimum control packet receiving interval of the local end.

A static BFD session supports this command only when it is in IPv4 or IPv6 control packet mode used for multihop detection.

Examples

# Set the minimum interval for receiving multihop BFD control packets to 500 milliseconds.

<Sysname> system-view

[Sysname] bfd multi-hop min-receive-interval 500

bfd multi-hop min-transmit-interval

Use bfd multi-hop min-transmit-interval to set the minimum interval for transmitting multihop BFD control packets.

Use undo bfd multi-hop min-transmit-interval to restore the default.

Syntax

bfd multi-hop min-transmit-interval interval

undo bfd multi-hop min-transmit-interval

Default

The minimum interval for transmitting multihop BFD control packets is 1000 milliseconds.

Views

System view

Static BFD session view

Predefined user roles

network-admin

Parameters

interval: Specifies the minimum interval for transmitting multihop BFD control packets, in milliseconds.

Support for this parameter depends on the MPU model. The following compatibility matrix shows the value ranges for the parameter:

MPU models	Value ranges
MSU-100	10 to 10000
MSU-200	10 to 10000
MSU-400-G	5 to 10000

‌

Usage guidelines

Use this command to prevent the BFD packet sending rate from exceeding the device capability.

The actual BFD control packet transmitting interval on the local end is the greater value between the following values:

· Minimum interval for transmitting BFD control packets on the local end.

· Minimum interval for receiving BFD control packets on the peer end.

A static BFD session supports this command only when it is in IPv4 or IPv6 control packet mode used for multihop detection.

Examples

# Set the minimum interval for transmitting multihop BFD control packets to 500 milliseconds.

<Sysname> system-view

[Sysname] bfd multi-hop min-transmit-interval 500

bfd session init-mode

Use bfd session init-mode to configure the mode for establishing a BFD session.

Use undo bfd session init-mode to restore the default.

Syntax

bfd session init-mode { active | passive }

undo bfd session init-mode

Default

BFD uses the active mode.

Views

System view

Predefined user roles

network-admin

Parameters

active: Specifies the active mode. In active mode, BFD actively transmits BFD control packets to the remote device, regardless of whether it receives a BFD control packet from the remote device.

passive: Specifies the passive mode. In passive mode, BFD does not actively transmit a BFD control packet to the remote end; it transmits a BFD control packet only after receiving a BFD control packet from the remote end.

Usage guidelines

A minimum of one end must operate in active mode for a BFD session to be established.

BFD version 0 does not support this command. The configuration does not take effect.

Examples

# Configure the session establishment mode as passive.

<Sysname> system-view

[Sysname] bfd session init-mode passive

bfd session-negotiation delay-upon-down

Use bfd session-negotiation delay-upon-down to enable session negotiation delay for down BFD sessions and set a delay timer.

Use undo bfd session-negotiation delay-upon-down to restore the default.

Syntax

bfd session-negotiation delay-upon-down interval

undo bfd session-negotiation delay-upon-down

Default

Session negotiation delay is disabled for down BFD sessions.

Views

System view

Predefined user roles

network-admin

Parameters

interval: Specifies a delay timer in the range of 1 to 1200 seconds.

Usage guidelines

If an upper-layer protocol uses BFD to detect the active path, an active/standby path switchover is triggered after the active path goes down. If the BFD session comes up before the active path recovers, the traffic on the standby path will be switched over to the active path. In this case, traffic loss will occur.

The session negotiation delay function starts a delay timer for each BFD session from up to down state and each newly created session. Before the timer expires, the device does not perform session negotiation on each BFD session. The delay timer allows the active path to recover completely before the BFD session comes up again.

Examples

# Enable session negotiation delay for down BFD sessions and set the delay timer to 6 seconds.

<Sysname> system-view

[Sysname] bfd session-negotiation delay-upon-down 6

Related commands

display bfd session

bfd session-negotiation delay-upon-reboot

Use bfd session-negotiation delay-upon-reboot to enable BFD session negotiation delay upon a device reboot and set a delay timer.

Use undo bfd session-negotiation delay-upon-reboot to restore the default.

Syntax

bfd session-negotiation delay-upon-reboot interval

undo bfd session-negotiation delay-upon-reboot

Default

BFD session negotiation delay upon a device reboot is disabled.

Views

System view

Predefined user roles

network-admin

Parameters

interval: Specifies a delay timer in the range of 1 to 1200 seconds.

Usage guidelines

If an upper-layer protocol uses BFD to detect the active path, an active/standby path switchover is triggered upon a device reboot. If the BFD session comes up after a device reboot, the traffic on the standby path will be switched over to the active path. In this case, traffic loss will occur if the active path of the upper-layer protocol has not recovered completely.

The session negotiation delay function starts a delay timer when the device reboots successfully. Before this timer expires, the device does not perform session negotiation on BFD sessions in down state or newly created sessions. The delay timer allows the active path to recover completely before the BFD session comes up again.

If both the bfd session-negotiation delay-upon-reboot and bfd session-negotiation delay-upon-down commands are executed, the device uses the longer delay time configured in the two commands after a reboot.

Examples

# Enable BFD session negotiation delay upon a device reboot and set the delay timer to 6 seconds.

<Sysname> system-view

[Sysname] bfd session-negotiation delay-upon-reboot 6

Related commands

bfd session-negotiation delay-upon-down

display bfd session

bfd static

Use bfd static to create a static BFD session and enter its view, or enter the view of an existing static BFD session.

Use undo bfd static to delete a static BFD session and all its settings.

Syntax

Static BFD session for single-hop detection with IPv4 control packets:

bfd static session-name [ peer-ip ipv4-address interface interface-type interface-number source-ip ipv4-address ]

undo bfd static session-name

Static BFD session for multihop detection with IPv4 control packets:

bfd static session-name [ peer-ip ipv4-address [ vpn-instance vpn-instance-name ] source-ip ipv4-address [ track-interface interface-type interface-number ] ]

undo bfd static session-name

Static BFD session for single-hop detection with IPv4 echo packets:

bfd static session-name [ peer-ip ipv4-address interface interface-type interface-number destination-ip ipv4-address [ source-ip ipv4-address ] one-arm-echo [ discriminator auto ] ]

undo bfd static session-name

Static BFD session for multihop detection with IPv4 echo packets:

bfd static session-name [ peer-ip ipv4-address [ vpn-instance vpn-instance-name ] destination-ip ipv4-address [ source-ip ipv4-address ] one-arm-echo [ discriminator auto ] ]

undo bfd static session-name

Static BFD session for single-hop detection with IPv6 control packets:

bfd static session-name [ peer-ipv6 ipv6-address interface interface-type interface-number source-ipv6 ipv6-address ]

undo bfd static session-name

Static BFD session for multihop detection with IPv6 control packets:

bfd static session-name [ peer-ipv6 ipv6-address [ vpn-instance vpn-instance-name ] source-ipv6 ipv6-address [ track-interface interface-type interface-number ] ]

undo bfd static session-name

Static BFD session for single-hop detection with IPv6 echo packets:

bfd static session-name [ peer-ipv6 ipv6-address interface interface-type interface-number destination-ipv6 ipv6-address [ source-ipv6 ipv6-address ] one-arm-echo [ discriminator auto ] ]

undo bfd static session-name

Static BFD session for multihop detection with IPv6 echo packets:

bfd static session-name [ peer-ipv6 ipv6-address [ vpn-instance vpn-instance-name ] destination-ipv6 ipv6-address [ source-ipv6 ipv6-address ] one-arm-echo [ discriminator auto ] ]

Static BFD session for single-hop detection with IPv4 control packets (the peer address is fixed at 224.0.0.184):

bfd static session-name [ peer-ip default-ip interface interface-type interface-number source-ip ip-address ]

undo bfd static session-name

Default

No static BFD sessions exist.

Views

System view

Predefined user roles

network-admin

Parameters

session-name: Specifies a static BFD session name, a case-sensitive string of 1 to 64 characters.

peer-ip ipv4-address: Specifies the peer IPv4 address in dotted decimal notation. It must be a valid unicast IPv4 address. For a static BFD session in control packet mode, the peer IPv4 address and the source IPv4 address determine the path to be detected. For a static BFD session in echo packet mode, the peer IPv4 address and the destination IPv4 address determine the path to be detected.

peer-ipv6 ipv6-address: Specifies the peer IPv6 address. For a static BFD session in control packet mode, the peer IPv6 address and the source IPv6 address determine the path to be detected. For a static BFD session in echo packet mode, the peer IPv6 address and the destination IPv6 address determine the path to be detected.

default-ip: Specifies the peer IPv4 address as 224.0.0.184.

vpn-instance vpn-instance-name: Specifies an MPLS L3VPN instance by its name, a case-sensitive string of 1 to 31 characters. If you do not specify this option, the static BFD session belongs to the public network.

interface interface-type interface-number: Specifies an interface by its type and number. BFD uses the specified interface as the outgoing interface for outgoing packets.

destination-ip ipv4-address: Specifies the destination IPv4 address for echo packets, in dotted decimal notation. It must be a valid unicast IPv4 address of the local end.

destination-ipv6 ipv6-address: Specifies the destination IPv6 address for echo packets. It must be the IPv6 address of the local end.

source-ip ipv4-address: Specifies the source IPv4 address for BFD packets, in dotted decimal notation. It must be a valid unicast IPv4 address.

source-ipv6 ipv6-address: Specifies the source IPv6 address for BFD packets.

one-arm-echo: Specifies the static BFD session mode as echo packet mode.

discriminator: Specifies BFD session discriminators.

auto: Enables the device to automatically assign local discriminator values to static BFD sessions.

track-interface interface-type interface-number: Specifies an interface monitored by the static BFD session. When the monitored interface fails, the static BFD session changes to the down state. If you do not specify this option, the static BFD session does not monitor any interfaces.

Usage guidelines

Application scenarios

A static BFD session can be used for single-hop detection and multihop detection.

Operating mechanism

For a static BFD session in control packet mode, the source IP address of BFD packets is the IP address specified for the source-ip/source-ipv6 keyword, and the destination IP address is the IP address specified for the peer-ip/peer-ipv6 keyword.

For a static BFD session in echo packet mode, the source IP address of BFD packets is the IP address specified for the source-ip/source-ipv6 keyword, and the destination IP address is the IP address specified for the destination-ip/destination-ipv6 keyword. If no source IP address is specified, the device uses the IP address specified in the destination-ip or destination-ipv6 command as the source IP address of echo packets.

Recommended configuration

A static BFD session can monitor the following interfaces:

· Layer 3 Ethernet interfaces and their subinterfaces.

· Layer 3 aggregate interfaces and their subinterfaces and member ports.

Restrictions and guidelines

If a static BFD session in control packet mode is created on the peer device, you must use this command to create a static BFD session on the local device. The BFD session discriminators must match on the local and peer devices. For example, if you execute the bfd static abc peer-ip 20.1.1.1 source-ip 20.1.1.2 command in system view and the discriminator local 513 and discriminator remote 514 commands in static BFD session on the local device, you must execute the bfd static abc peer-ip 20.1.1.2 source-ip 20.1.1.1 command and the discriminator local 514 and discriminator remote 513 commands on the peer device.

When creating a static BFD session, you must specify a peer IP address. The system checks only the format of the IP address but not its correctness. If the peer IPv4 or IPv6 address is incorrect, the static BFD session cannot be established. The bfd static session-name command without any parameters specified can only be used to enter the view of an existing static BFD session.

For a static BFD session in control packet mode, you must use the discriminator command to specify its local and remote discriminators. Otherwise, the static BFD session does not take effect.

You need to create a static BFD session on only the local device if you use the echo packet mode for detection. As a best practice, specify the source IP address for echo packets when creating a static BFD session. Make sure the specified source IP address does not belong to the subnet where a local interface resides. Without a source IP address specified, the device uses the IP address specified in the bfd echo-source-ip or bfd echo-source-ipv6 command as the source IP address of echo packets. If you do not specify the source IP address by using either method, the device uses the IP address specified in the destination-ip or destination-ipv6 command as the source IP address of echo packets.

To use a static BFD session in control packet mode for single-hop detection, you must perform the following configuration:

· Specify the IP address of the peer interface for the peer-ip/peer-ipv6 keyword.

· Specify the IP address of the local interface for the source-ip/source-ipv6 keyword.

To modify a static BFD session, delete the static BFD session and then configure a new static BFD session.

Different static BFD sessions cannot have the same local discriminator.

To detect data link layer connectivity for an interface, execute one of the following commands:

· bfd detect-interface source-ip

· bfd static session-name peer-ip default-ip interface interface-type interface-number source-ip ip-address

Use the IP address of the interface as the source IP address. If the interface does not have an IP address, specify a unicast IP address other than 0.0.0.0. An interface can use only one static BFD session to detect data link layer connectivity.

Examples

# Create a static BFD session and enter its view. The static BFD session detects the path between 1.1.1.1 and 1.1.1.2 and uses GigabitEthernet 1/0/1 to send BFD packets with source IP address 1.1.1.1 and destination IP address is 1.1.1.2. The local discriminator is 1537, and the remote discriminator is 2048.

<Sysname> system-view

[Sysname] bfd static abc peer-ip 1.1.1.2 interface gigabitethernet 1/0/1 source-ip 1.1.1.1 discriminator local 1537 remote 2048

[Sysname-bfd-static-session-abc]

# Create a static BFD session in echo mode and enter its view. The static BFD session detects the path between 1.1.1.1 and 1.1.1.2 and uses GigabitEthernet 1/0/1 to send BFD packets with source IP address 9.9.9.9 and destination IP address is 1.1.1.2.

<Sysname> system-view

[Sysname] bfd static abc peer-ip 1.1.1.1 interface gigabitethernet 1/0/1 destination-ip 1.1.1.2 source-ip 9.9.9.9 one-arm-echo discriminator auto

[Sysname-bfd-static-session-abc]

Related commands

bfd detect-interface source-ip

bfd echo-source-ip

bfd echo-source-ipv6

discriminator

bfd template

Use bfd template to create a BFD template and enter its view, or enter the view of an existing BFD template.

Use undo bfd template to delete the BFD template.

Syntax

bfd template template-name

undo bfd template template-name

Default

No BFD templates exist.

Views

System view

Predefined user roles

network-admin

Parameters

template-name: Specifies the template name, a case-sensitive string of 1 to 63 characters.

Examples

# Create BFD template bfd1 and enter BFD template view.

<Sysname> system-view

[Sysname] bfd template bfd1

[Sysname-bfd-template-bfd1]

bfd ttl

Use bfd ttl to specify the TTL value for BFD packets.

Use undo bfd ttl to restore the default.

Syntax

bfd { peer-ip ipv4-address mask-length | peer-ipv6 ipv6-address prefix-length } ttl { single-hop | multi-hop } ttl-value

undo bfd { peer-ip ipv4-address mask-length | peer-ipv6 ipv6-address prefix -length } ttl { single-hop | multi-hop }

Default

The TTL value of a single-hop BFD packet is 255. The TTL value of a multihop BFD packet is 64.

Views

System view

Predefined user roles

network-admin

Parameters

peer-ip ipv4-address mask-length: Specifies a peer IPv4 address range for the BFD session. The ipv4-address argument represents a valid unicast IPv4 address in dotted decimal notion. The mask-length argument represents the mask length in the range of 8 to 32.

peer-ipv6 ipv6-address prefix-length: Specifies a peer IPv6 address range for the BFD session. The ipv6-address argument represents an IPv6 address. The prefix-length argument represents a prefix length in the range of 16 to 128.

single-hop: Specifies single-hop BFD sessions.

multi-hop: Specifies multihop BFD sessions.

ttl-value: Specifies the TTL value for BFD packets, in the range of 1 to 255.

Usage guidelines

When you connect an H3C device to a device from another vendor, for successful BFD session negotiation, make sure the TTL value settings for BFD packets on both ends of the BFD session are the same. When the device receives a BFD packet in DOWN or INIT state from its peer, it verifies the TTL value of the packet and performs one of the following actions:

· For a single-hop BFD session, if the device receives a packet that carries a TTL value that is different from the TTL value specified with this command, the device drops the packet.

· For a multihop BFD session, if the device receives a packet that carries a TTL value that is greater than the TTL value specified with this command, the device drops the packet.

· If the BFD session is already up, the device sets the BFD session state to AdminDown, which triggers a BFD session renegotiation.

Follow these guidelines when you set the TTL value for BFD packets:

· This command does not take effect on BFD sessions in echo packet mode.

· The device does not verify the TTL value in SBFD packets.

· For an IPv4 or IPv6 address with different mask lengths or prefix lengths, the device uses the TTL value specified with the longest mask or prefix length. For example, if the peer IP address of a BFD session is 10.10.10.1 and the following commands are configured, the device uses TTL value 253 for BFD packets.

¡ bfd peer-ip 10.10.10.0 23 ttl single-hop 254

¡ bfd peer-ip 10.10.10.0 24 ttl single-hop 253

For an IPv4 or IPv6 subnet, the TTL value of single-hop BFD packets must be greater than the TTL value of multihop BFD packets.

Examples

# Set the TTL value of single-hop BFD packets to 254, and specify the peer IP address of the BFD session as 10.10.10.0 and the mask length as 24.

<Sysname> system-view

[Sysname] bfd peer-ip 10.10.10.0 24 ttl single-hop 254

Related commands

display bfd ttl

discriminator

Use discriminator to specify the local and remote discriminators for a static BFD session.

Use undo discriminator to remove the local and remote discriminators for the static BFD session.

Syntax

discriminator { local local-value | remote remote-value }

undo discriminator { local local-value | remote remote-value }

Default

No local and remote discriminators are specified for a static BFD session.

Views

Static BFD session view

Predefined user roles

network-admin

Parameters

local local-value: Specifies the local discriminator in the range of 1 to 32768.

remote remote-value: Specifies the remote discriminator in the range of 1 to 4294967295.

Usage guidelines

Use this command only if you do not specify the local or remote discriminator when creating a static BFD session.

To modify the local or remote discriminator of a static BFD session, execute the undo discriminator and then the discriminator command to specify a new local or remote discriminator.

Different static BFD sessions cannot have the same local discriminator.

Examples

# Create local discriminator 1537 and remote discriminator 2048 for static BFD session abc.

<Sysname> system-view

[Sysname] bfd static abc

[Sysname-bfd-static-session-abc] discriminator local 1537

[Sysname-bfd-static-session-abc] discriminator remote 2048

Related commands

bfd static

display bfd session

Use display bfd session to display BFD session information.

Syntax

display bfd session [ discriminator local-value | discriminator local local-value | static name session-name | verbose ]

display bfd session [ [ dynamic ] [ control | echo ] [ ip ] [ state { admin-down | down | init | up } ] [ discriminator remote remote-value ] [ peer-ip { ipv4-address | default-ip } [ vpn-instance vpn-instance-name ] ] [ verbose ] ]

display bfd session [ [ dynamic ] [ control | echo ] [ ipv6 ] [ state { admin-down | down | init | up } ] [ discriminator remote remote-value ] [ peer-ipv6 ipv6-address [ vpn-instance vpn-instance-name ] ] [ verbose ] ]

display bfd session [ [ dynamic ] [ control | echo ] [ lsp | te | pw ] [ state { admin-down | down | init | up } ] [ discriminator remote remote-value ] [ [ peer-ip ipv4-address [ vpn-instance vpn-instance-name ] ] | [ peer-ipv6 ipv6-address [ vpn-instance vpn-instance-name ] ] ] [ verbose ] ]

display bfd session [ [ static ] [ ip ] [ state { admin-down | down | init | up } ] [ discriminator remote remote-value ] [ peer-ip { ipv4-address | default-ip } [ vpn-instance vpn-instance-name ] ] [ verbose ]

display bfd session [ [ static ] [ ipv6 ] [ state { admin-down | down | init | up } ] [ discriminator remote remote-value ] [ peer-ipv6 ipv6-address [ vpn-instance vpn-instance-name ] ] [ verbose ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

discriminator local-value: Specifies a BFD session by its local discriminator in the range of 1 to 4294967295. If you do not specify a BFD session, this command displays information about all BFD sessions.

discriminator local local-value: Specifies a BFD session by its local discriminator in the range of 1 to 4294967295. If you do not specify a BFD session, this command displays information about all BFD sessions.

name session-name: Specifies a static BFD session by its name, a case-sensitive string of 1 to 15 characters.

dynamic: Specifies dynamic BFD sessions.

static: Specifies static BFD sessions.

control: Specifies BFD sessions in control packet mode.

echo: Specifies BFD sessions in echo mode.

ip: Specifies BFD sessions used to detect IPv4 links.

ipv6: Specifies BFD sessions used to detect IPv6 links.

lsp: Specifies BFD sessions used to detect MPLS LSPs.

te: Specifies BFD sessions used to detect MPLS TE tunnels.

pw: Specifies BFD sessions used to detect PWs.

state: Displays BFD sessions by session state.

down: Specifies BFD sessions in Down state.

admin-down: Specifies BFD sessions in AdminDown state.

init: Specifies BFD sessions in Init state.

up: Specifies BFD sessions in Up state.

discriminator remote remote-value: Specifies a BFD session by its remote discriminator in the range of 1 to 4294967295.

peer-ip ipv4-address: Specifies a BFD session by the peer IPv4 address in dotted decimal notation.

peer-ipv6 ipv6-address: Specifies a BFD session by the peer IPv6 address.

default-ip: Specifies the peer IPv4 address as 224.0.0.184.

vpn-instance vpn-instance-name: Specifies an MPLS L3VPN instance by its name, a case-sensitive string of 1 to 31 characters. If you do not specify this option, the command displays the BFD sessions of the public network.

verbose: Displays detailed BFD session information. If you do not specify this keyword, the command displays brief BFD session information.

Usage guidelines

If you do not specify the dynamic or static keyword, this command displays all dynamic and static BFD sessions.

The discriminator local-value and discriminator local local-value parameters have the same effect. The only difference is that you do not need to enter local when using the latter.

Examples

# Display brief information about all BFD sessions.

<Sysname> display bfd session

Total sessions: 5 Up sessions: 5 Init mode: Active

IPv4 session working in control mode:

LD/RD SourceAddr DestAddr State Running Up for Holdtime

Interface

513/513 1.1.1.1 1.1.1.2 Up 00:00:12 2297ms

GE1/0/1

IPv6 session working in control mode:

Local discr: 513 Remote discr: 513

Source IP: FE80::20C:29FF:FED4:7171

Destination IP: FE80::20C:29FF:FE72:AC4D

Session state: Up Interface: GE1/0/2

Hold time: 2142ms Running Up for: 00:05:22

IPv4 static session working in echo packet mode:

LD SourceAddr DestAddr State Running Up for Holdtime

Interface

327 192.168.1.101 192.168.1.83 Up 00:04:19 2050ms

GE1/0/1

MPLS LSP session working in control packet mode:

LD/RD SourceAddr DestAddr State Running Up for Holdtime

Interface

32769/32769 2.2.2.9 127.0.0.1 Up 00:05:16 4990ms

N/A

MPLS TE session working in echo mode:

LD SourceAddr DestAddr State Running Up for Holdtime

Interface

32777 1.1.1.1 3.3.3.3 Up 00:10:52 4430ms

Tun0

MPLS PW session working in control packet mode:

LD/RD SourceAddr DestAddr State Running Up for Holdtime

Interface

20481/20481 2.2.2.2 127.0.0.1 Up 00:10:55 2489ms

N/A

Table 3 Command output

Field	Description
Total Session Num	Total number of BFD sessions.
Up Session Num	Total number of active BFD sessions.
Init Mode	BFD operating mode: Active or passive.
XX session working in yy mode	BFD session type and operating mode: · IPv4 session working in control mode—IPv4 session in control mode. · IPv4 session working in echo mode. · IPv6 session working in control mode—IPv6 session in control mode. · IPv6 session working in echo mode. · IPv4 static session working in control packet mode. · IPv6 static session working in control packet mode. · MPLS LSP session working in control packet mode—BFD session in control mode used to detect failures in an LSP. · MPLS LSP session working in echo mode—BFD session in echo mode used to detect failures in an LSP. · MPLS TE session working in control packet mode. · MPLS TE session working in echo mode. · MPLS PW session working in control packet mode. · IPv6 SR policy session working in echo mode—BFD session in echo mode used to detect failures in an SRv6 tunnel. (This value is not supported in the current software version.) · IPv4 SDWAN session working in control packet mode. (This field is not supported in the current software version.) · IPv6 SDWAN session working in control packet mode. (This field is not supported in the current software version.) · IPv6 SR policy session working in echo mode—BFD session in echo mode used to detect failures in an SRv6 TE policy. (This value is not supported in the current software version.)
LD/RD	Local discriminator/Remote discriminator of the session.
SourceAddr	Source IPv4 address of the session.
DestAddr	Destination IPv4 address of the session.
State	Session state: Down, Init, Adown, or Up.
Holdtime	Length of time before session detection timer expires. For a BFD session in Down state, this field displays 0ms.
Interface	Name of the interface of the session.
Local discr	Local discriminator of the session.
Remote discr	Remote discriminator of the session.
Source IP	Source IPv6 address of the session.
Destination IP	Destination IPv6 address of the session.
Session state	Session state: Down, Adown, Init, or Up.
Running Up for	Duration of the session in up state, in hh:mm:ss format. · hh—Represents the hours. · mm—Represents the minutes. · ss—Represents the seconds.
Hold time	Length of time before session detection timer expires. For a BFD session in Down state, this field displays 0ms.

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# Display detailed BFD session information.

<Sysname> display bfd session verbose

Total Session Num: 5 Up Session Num: 5 Init Mode: Active

IPv4 session working in control mode:

Local Discr: 513 Remote Discr: 513

Source IP: 1.1.1.1 Destination IP: 1.1.1.2

Destination port: 3784 Session State: Up

Interface: GigabitEthernet1/0/1

Min Tx Inter: 500ms Act Tx Inter: 500ms

Min Rx Inter: 500ms Detect Inter: 2500ms

Rx Count: 42 Tx Count: 43

Connect Type: Direct Running Up for: 00:00:20

Hold Time: 2078ms Auth Mode: None

Detect Mode: Async Slot: 0

Protocol: OSPF

Version: 1 TTL: 255

Diag Info: No Diagnostic

IPv6 session working in control mode:

Local Discr: 513 Remote Discr: 513

Source IP: FE80::20C:29FF:FED4:7171

Destination IP: FE80::20C:29FF:FE72:AC4D

Destination port: 3784 Session State: Up

Interface: GigabitEthernet1/0/2

Min Tx Inter: 500ms Act Tx Inter: 500ms

Min Rx Inter: 500ms Detect Inter: 25000ms

Rx Count: 38 Tx Count: 38

Connect Type: Direct Running Up for: 00:00:15

Hold Time: 2211ms Auth Mode: None

Detect Mode: Async Slot: 0

Protocol: OSPFv3

Version: 1 TTL: 255

Diag Info: No Diagnostic

IPv4 session working in control mode:

Session name: abc

Local Discr: 310 Remote Discr: 308

Source IP: 12.1.1.1 Destination IP: 12.1.1.2

Destination port: 3784 Session State: Up

Interface: GigabitEthernet1/0/1

Min Tx Inter: 500ms Act Tx Inter: 5000ms

Min Rx Inter: 500ms Detect Inter: 25000ms

Rx Count: 514 Tx Count: 514

Connect Type: Direct Running Up for: 00:00:15

Hold Time: 2120ms Auth Mode: None

Detect Mode: Async Slot: 0

Protocol: STATIC_IPv4

Version: 1 TTL: 255

Diag Info: No Diagnostic

IPv6 session working in control mode:

Session name: bbbb

Local Discr: 1700 Remote Discr: 1700

Source IP: FE80::20C:29FF:FED4:7171

Destination IP: FE80::20C:29FF:FE72:AC4D

Destination port: 3784 Session State: Up

Interface: GigabitEthernet1/0/2

Min Tx Inter: 500ms Act Tx Inter: 5000ms

Min Rx Inter: 500ms Detect Inter: 25000ms

Rx Count: 38 Tx Count: 38

Connect Type: Direct Running Up for: 00:00:15

Hold Time: 2211ms Auth Mode: None

Detect Mode: Async Slot: 0

Protocol: STATIC_IPv6

Version: 1 TTL: 255

Diag Info: No Diagnostic

MPLS LSP session working in control packet mode:

Local Discr: 32769 Remote Discr: 32769

Source IP: 3.3.3.9 Destination IP: 2.2.2.9

Destination port: 4784 Session State: Up

Interface: N/A

Min Tx Inter: 1000ms Act Tx Inter: 1000ms

Min Rx Inter: 1000ms Detect time: 5000ms

Rx Count: 1778 Tx Count: 1669

Connect Type: Indirect Running Up for: 00:24:14

Hold Time: 4248ms Auth Mode: None

Detect Mode: Async Slot: 0

Protocol: MPLS_LSPV

Version: 1 TTL: 255

Diag Info: No Diagnostic

MPLS TE session working in echo mode:

Local Discr: 32777

Source IP: 1.1.1.1 Destination IP: 3.3.3.3

Destination port: 3785 Session State: Up

Interface: Tunnel0

Hold Time: 4450ms Act Tx Inter: 1000ms

Min Rx Inter: 1000ms Detect Time: 5000ms

Rx Count: 320 Tx Count: 320

Connect Type: Indirect Running Up for: 00:04:35

Detect Mode: Async Slot: 0

Protocol: MPLS_LSPV

Version: 1

Diag Info: No Diagnostic

MPLS PW session working in control packet mode:

Local Discr: 20481 Remote Discr: 20481

Source IP: 2.2.2.2 Destination IP: 127.0.0.1

Destination port: 3784 Session State: Up

Interface: N/A

Min Tx Inter: 500ms Act Tx Inter: 500ms

Min Rx Inter: 500ms Detect Time: 2500ms

Rx Count: 72 Tx Count: 73

Connect Type: Indirect Running Up for: 00:00:30

Hold Time: 2489ms Auth Mode: None

Detect Mode: Async Slot: 0

Protocol: MPLS_LSPV

Version: 1 TTL: 255

Diag Info: No Diagnostic

Table 4 Command output

Field	Description
Total Session Num	Total number of BFD sessions.
Up Session Num	Total number of active BFD sessions.
Init Mode	BFD operating mode: Active or passive.
XX session working in yy mode	BFD session type and operating mode: · IPv4 session working in control mode—IPv4 session in control mode. · IPv4 session working in echo mode. · IPv6 session working in control mode—IPv6 session in control mode. · IPv6 session working in echo mode. · IPv4 static session working in control packet mode. · IPv6 static session working in control packet mode. · MPLS LSP session working in control packet mode—BFD session in control mode used to detect failures in an LSP. · MPLS LSP session working in echo mode—BFD session in echo mode used to detect failures in an LSP. · MPLS TE session working in control packet mode. · MPLS TE session working in echo mode. · MPLS PW session working in control packet mode. · IPv6 SR session working in echo mode—BFD session in echo mode used to detect failures in an SRv6 tunnel. (This value is not supported in the current software version.) · IPv4 SDWAN session working in control packet mode. (This field is not supported in the current software version.) · IPv6 SDWAN session working in control packet mode. (This field is not supported in the current software version.) · IPv6 SR policy session working in echo mode—BFD session in echo mode used to detect failures in an SRv6 TE policy. (This value is not supported in the current software version.)
Session name	Static BFD session name. This field appears only for a static BFD session.
Local Discr	Local discriminator of the session.
Remote Discr	Remote discriminator of the session.
Source IP	Source IP address of the session.
Destination IP	Destination IP address of the session.
Destination port	Destination port number in BFD packets defined in Comware: · The destination port number in single-hop BFD control packets is 3784. · The destination port number in single-hop or multihop BFD echo packets is 3785. · The destination port number in multihop BFD control packets is 4784. · The destination port number in BFD control packets for association between link aggregation and BFD is 6784. The device uses the destination port number in incoming packets that are not defined in Comware as the destination port number in outgoing BFD packets.
Session State	Session state: Down, Adown, Init, or Up.
Interface	Name of the interface of the session.
Min Tx Inter	Minimum transmit interval.
Min Rx Inter	Minimum receive interval.
Act Tx Inter	Actual transmit interval.
Detect Inter	Actual session detection timer.
Rx Count	Number of packets received.
Tx Count	Number of packets sent.
Hold Time	Length of time before session detection timer expires.
Auth Mode	Session authentication mode.
Connect Type	Connection type of the interface: Direct or indirect.
Running Up for	Duration of the session in up state, in hh:mm:ss format. · hh—Represents the hours. · mm—Represents the minutes. · ss—Represents the seconds.
Detect Mode	Detection mode: · Async—Asynchronous mode. · Demand—Demand mode. · Async/Echo—Asynchronous mode with echo detection enabled. · Demand/Echo—Demand mode with echo detection enabled.
Slot	Slot number of the card where the BFD session resides.
Delay-up hold time	Remaining time of the delay timer, in seconds. If BFD session negotiation delay is not configured or the delay timer has expired, this field is not displayed.
Protocol	Protocol associated with BFD: · OSPF. · ISIS_BR_L1—IS-IS with the network type as broadcast and the router type as Level 1. · ISIS_BR_L2—IS-IS with the network type as broadcast and the router type as Level 2. · ISIS_P2P—IS-IS with the network type as P2P. · ISIS6_BR_L1—IPv6 IS-IS with the network type as broadcast and the router type as Level 1. · ISIS6_BR_L2—IPv6 IS-IS with the network type as broadcast and the router type as Level 2. · ISIS6_P2P—IPv6 IS-IS with the network type as P2P. · BGP. · MPLS_RSVP. · STATIC4—IPv4 static routing. · TRACK—Track. · RIP. · IPFRR—FIB IP FRR. · MAD. · MPLS_LSPV. · OSPFv3. · BGP4+. · PIM. · PIM6—IPv6 PIM. · STATIC6—IPv6 static routing. · RIPNG—RIPng. · Interface—Interface state. · TUNNEL. · VTEP. · LAGG—Link aggregation. · STATIC_IPv4—IPv4 static BFD session. · STATIC_IPv6—IPv6 static BFD session. · SDWAN—BFD session for SDWAN tunnels. (This field is not supported in the current software version.)
Diag Info	Diagnostic information about the session: · No Diagnostic. · Control Detection Time Expired—A control-mode BFD session goes down because local detection times out. · Echo Function Failed—An echo-mode BFD session goes down, because local detection times out or the source IP address of echo packets is deleted. · Neighbor Signaled Session Down—The remote end notifies the local end of BFD session down. · Administratively Down—The local system prevents a BFD session from being established.

‌

display bfd ttl

Use display bfd ttl to display the TTL values for BFD packets.

Syntax

display bfd ttl

Views

Any view

Predefined user roles

network-admin

network-operator

Examples

# Display the TTL values for BFD packets.

<Sysname> display bfd ttl

Peer IP Mask length Type TTL value

-------------------------------------------------------------------------------

10.10.10.0 24 single-hop 255

10.1.1.0 25 multi-hop 254

Peer IPv6 Prefix length Type TTL value

-------------------------------------------------------------------------------

10:1:: 64 single-hop 255

11:1:: 96 multi-hop 255

Table 5 Command output

Field	Description
Peer IP	Peer IPv4 address of the BFD session.
Peer IPv6	Peer IPv6 address of the BFD session.
Mask length	Mask length of the IPv4 address.
Prefix length	Prefix length of the IPv6 address.
Type	Detection type of the BFD session: · single-hop—Single-hop detection. · multi-hop—Multihop detection.
TTL value	TTL value of BFD packets.

‌

Related commands

bfd ttl

reset bfd session statistics

Use reset bfd session statistics to clear the BFD session statistics.

Syntax

reset bfd session statistics

Views

User view

Predefined user roles

network-admin

Examples

# Clear the BFD session statistics.

<Sysname> reset bfd session statistics

snmp-agent trap enable bfd

Use snmp-agent trap enable bfd to enable SNMP notifications for BFD.

Use undo snmp-agent trap enable bfd to disable SNMP notifications for BFD.

Syntax

snmp-agent trap enable bfd

undo snmp-agent trap enable bfd

Default

All SNMP notifications are enabled for BFD.

Views

System view

Predefined user roles

network-admin

Usage guidelines

To report critical BFD events to an NMS, enable SNMP notifications for BFD. For BFD event notifications to be sent correctly, you must also configure SNMP as described in the network management and monitoring configuration guide for the device.

Examples

# Disable SNMP notifications for BFD.

<Sysname> system-view

[Sysname] undo snmp-agent trap enable bfd

SBFD commands

bfd detect-multiplier

Use bfd detect-multiplier to set the detection time multiplier in BFD template view.

Use undo bfd detect-multiplier to restore the default.

Syntax

bfd detect-multiplier value

undo bfd detect-multiplier

Default

The detection time multiplier is 3.

Views

BFD template view

Predefined user roles

network-admin

Parameters

value: Specifies a detection time multiplier. The value range for this argument is 3 to 50.

Usage guidelines

The detection time multiplier determines the maximum number of SBFD control packets that an initiator can discard continuously.

The detection time is the detection time multiplier of the initiator multiplied by the minimum SBFD packet sending interval of the initiator.

Examples

# In BFD template abc, set the detection time multiplier to 6.

<Sysname> system-view

[Sysname] bfd template abc

[Sysname-bfd-template-abc] bfd detect-multiplier 6

bfd min-transmit-interval

Use bfd min-transmit-interval to set the minimum interval for transmitting SBFD control packets in BFD template view.

Use undo bfd min-transmit-interval to restore the default.

Syntax

bfd min-transmit-interval interval

undo bfd min-transmit-interval

Default

The minimum interval for transmitting SBFD control packets is 1000 milliseconds.

Views

BFD template view

Predefined user roles

network-admin

Parameters

interval: Specifies the minimum interval for transmitting SBFD control packets, in milliseconds. The value range is 10 to 10000.

Usage guidelines

Use this command to prevent the SBFD control packet sending rate from exceeding the device capability.

The actual SBFD control packet transmitting interval is the set minimum interval.

Examples

# In BFD template abc, set the minimum interval for transmitting SBFD control packets to 500 milliseconds.

<Sysname> system-view

[Sysname] bfd template abc

[Sysname-bfd-template-abc] bfd min-transmit-interval 500

Related commands

bfd detect-multiplier

bfd multi-hop detect-multiplier

Use bfd multi-hop detect-multiplier to set the SBFD detection time multiplier in system view.

Use undo bfd multi-hop detect-multiplier to restore the default.

Syntax

bfd multi-hop detect-multiplier value

undo bfd multi-hop detect-multiplier

Default

The SBFD detection time multiplier is 3.

Views

System view

Predefined user roles

network-admin

Parameters

value: Specifies a detection time multiplier. The value range for this argument is 3 to 50.

Usage guidelines

The detection time multiplier determines the maximum number of SBFD control packets that an initiator can discard continuously.

The detection time is the detection time multiplier of the initiator multiplied by the minimum SBFD packet sending interval of the initiator.

Examples

# Set the detection time multiplier to 6.

<Sysname> system-view

[Sysname] bfd multi-hop detect-multiplier 6

bfd multi-hop min-transmit-interval

Use bfd multi-hop min-transmit-interval to set the minimum interval for transmitting SBFD control packets in system view.

Use undo bfd multi-hop min-transmit-interval to restore the default.

Syntax

bfd multi-hop min-transmit-interval interval

undo bfd multi-hop min-transmit-interval

Default

The minimum interval for transmitting SBFD control packets is 1000 milliseconds.

Views

System view

Predefined user roles

network-admin

Parameters

interval: Specifies the minimum interval for transmitting SBFD control packets, in milliseconds.

Support for this parameter depends on the MPU model. The following compatibility matrix shows the value ranges for the parameter:

MPU models	Value ranges
MSU-100	10 to 10000
MSU-200	10 to 10000
MSU-400-G	5 to 10000

‌

Usage guidelines

Use this command to prevent the SBFD control packet sending rate from exceeding the device capability.

The actual SBFD control packet transmitting interval is the set minimum interval.

Examples

# Set the minimum interval for transmitting SBFD control packets to 500 milliseconds.

<Sysname> system-view

[Sysname] bfd multi-hop min-transmit-interval 500

bfd session-negotiation delay-upon-down

Use bfd session-negotiation delay-upon-down to enable session negotiation delay for down SBFD sessions and set a delay timer.

Use undo bfd session-negotiation delay-upon-down to restore the default.

Syntax

bfd session-negotiation delay-upon-down interval

undo bfd session-negotiation delay-upon-down

Default

Session negotiation delay is disabled for down SBFD sessions.

Views

System view

Predefined user roles

network-admin

Parameters

interval: Specifies a delay timer in the range of 1 to 1200 seconds.

Usage guidelines

If an upper-layer protocol uses SBFD to detect the active path, an active/standby path switchover is triggered after the active path goes down. If the SBFD session comes up before the active path recovers, the traffic on the standby path will be switched over to the active path. In this case, traffic loss will occur.

The session negotiation delay function starts a delay timer for each SBFD session from up to down state and each newly created session. Before the timer expires, the device does not perform session negotiation on each SBFD session. The delay timer allows the active path to recover completely before the SBFD session comes up again.

Examples

# Enable session negotiation delay for down SBFD sessions and set the delay timer to 6 seconds.

<Sysname> system-view

[Sysname] bfd session-negotiation delay-upon-down 6

Related commands

display bfd session

bfd session-negotiation delay-upon-reboot

Use bfd session-negotiation delay-upon-reboot to enable SBFD session negotiation delay upon a device reboot and set a delay timer.

Use undo bfd session-negotiation delay-upon-reboot to restore the default.

Syntax

bfd session-negotiation delay-upon-reboot interval

undo bfd session-negotiation delay-upon-reboot

Default

SBFD session negotiation delay upon a device reboot is disabled.

Views

System view

Predefined user roles

network-admin

Parameters

interval: Specifies a delay timer in the range of 1 to 1200 seconds.

Usage guidelines

If an upper-layer protocol uses SBFD to detect the active path, an active/standby path switchover is triggered upon a device reboot. If the SBFD session comes up after a device reboot, the traffic on the standby path will be switched over to the active path. In this case, traffic loss will occur if the active path of the upper-layer protocol has not recovered completely.

The session negotiation delay function starts a delay timer when the device reboots successfully. Before this timer expires, the device does not perform session negotiation on SBFD sessions in down state or newly created sessions. The delay timer allows the active path to recover completely before the SBFD session comes up again.

Examples

# Enable SBFD session negotiation delay upon a device reboot and set the delay timer to 6 seconds.

<Sysname> system-view

[Sysname] bfd session-negotiation delay-upon-reboot 6

Related commands

bfd session-negotiation delay-upon-down

display bfd session

bfd template

Use bfd template to create a BFD template and enter its view, or enter the view of an existing BFD template.

Use undo bfd template to delete the BFD template.

Syntax

bfd template template-name

undo bfd template template-name

Default

No BFD templates exist.

Views

System view

Predefined user roles

network-admin

Parameters

template-name: Specifies the template name, a case-sensitive string of 1 to 63 characters.

Examples

# Create BFD template bfd1 and enter BFD template view.

<Sysname> system-view

[Sysname] bfd template bfd1

[Sysname-bfd-template-bfd1]

display sbfd session

Use display sbfd session to display SBFD session information.

Syntax

display sbfd session { initiator [ discriminator value | [ ipv6 [ peer-ipv6 ipv6-address ] ] [ verbose ] | verbose ] | reflector [ discriminator value | verbose ] }

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

initiator: Displays SBFD session information for the initiator.

reflector: Displays SBFD session information for the reflector.

discriminator value: Specifies a local discriminator in the range of 1 to 4294967295.

ipv6: Specifies SBFD sessions used to detect IPv6 links.

peer-ipv6 ipv6-address: Specifies a SBFD session by the peer IPv6 address.

verbose: Displays detailed information about all SBFD sessions. If you do not specify this keyword, the command displays brief information about all SBFD sessions.

Usage guidelines

If you do not specify any keyword, this command displays brief information about all SBFD sessions.

Examples

# Display brief information about all SBFD sessions for the initiator.

<Sysname> display sbfd session initiator

Total Session Num: 2 Up Session Num: 2

SBFD session (MPLS LSP):

Local Discr: 1 Remote Discr: 1000001

Source IP: 1.1.1.1

Destination IP: 127.0.0.1

Session State: Up Hold Time: 2184ms

Running Up for: 00:04:50

Table 6 Command output

Field	Description
Total Session Num	Total number of SBFD sessions.
Up Session Num	Number of active SBFD sessions.
SBFD session (xxx)	Path to be detected by the SBFD session: · MPLS LSP. · SRv6 TE policy. (This field is not supported in the current software version.) · IPv6—IPv6 link.
Local Discr	Local discriminator of the session.
Remote Discr	Remote discriminator of the session.
Source IP	Source IP address of the session.
Destination IP	Destination IP address of the session.
Session State	Session state: Down or Up.
Hold Time	Length of time before the session detection timer expires, in milliseconds. For an SBFD session in Down state, this field displays 0ms.
Running Up for	Duration of the session in up state, in hh:mm:ss format. · hh—Represents the hours. · mm—Represents the minutes. · ss—Represents the seconds.

‌

# Display detailed information about the SBFD session with local discriminator 2 for the initiator.

<Sysname> display sbfd session initiator discriminator 2

Local Discr: 2 Remote Discr: 1000002

Source IP: 1.1.1.2 Destination IP: 127.0.0.2

Session State: Up Hold Time: 4130ms

Min Tx Inter: 500ms Act Tx Inter: 1000ms

Detect Inter: 5000ms Running Up for: 00:01:30

Rx Count: 100 Tx Count: 100

Slot: 0 NID: 22020097

Protocol: MPLS_LSPV

Diag Info: No Diagnostic

Template Name: abc

Table 7 Command output

Field	Description
Local Discr	Local discriminator of the session.
Remote Discr	Remote discriminator of the session.
Source IP	Source IP address of the session.
Destination IP	Destination IP address of the session.
Session State	Session state: Down or Up.
Hold Time	Length of time before the session detection timer expires, in milliseconds. For an SBFD session in Down state, this field displays 0ms.
Min Tx Inter	Minimum SBFD packet transmission interval in milliseconds.
Act Tx Inter	Actual SBFD packet transmission interval in milliseconds.
Detect Inter	Actual session detection timer in milliseconds.
Running Up for	Duration of the session in up state, in hh:mm:ss format. · hh—Represents the hours. · mm—Represents the minutes. · ss—Represents the seconds.
Rx Count	Number of packets received.
Tx Count	Number of packets sent.
Slot	Slot number of the card where the BFD session resides.
Color	This field is not supported in the current software version. Color attribute of the SRv6 TE policy.
NID	Forwarding entry index of the SID list. This field is displayed only when the index exists and is a non-zero value.
Diag Info	Diagnostic information about the session: · No Diagnostic. · Control Detection Time Expired—The SBFD session goes down because local detection times out. · Neighbor Signaled Session Down—The remote end notifies the local end of SBFD session down. · Concatenated Path Down—The SBFD session goes down because the concatenated path associated with the session fails.
Template Name	Template associated with the session. If no template is associated, this field is not displayed.

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# Display detailed information about all SBFD sessions for the initiator.

<Sysname> display sbfd session initiator verbose

Total Session Num: 2 Up Session Num: 2

SBFD session (MPLS LSP):

Local Discr: 1 Remote Discr: 1000001

Source IP: 1.1.1.1 Destination IP: 127.0.0.1

Session State: Up Hold Time: 4130ms

Min Tx Inter: 500ms Act Tx Inter: 1000ms

Detect Inter: 5000ms Running Up for: 00:01:30

Rx Count: 100 Tx Count: 100

Slot: 0 NID: 22020097

Protocol: MPLS_LSPV

Diag Info: No Diagnostic

Template Name: abc

Table 8 Command output

Field	Description
Total Session Num	Total number of SBFD sessions.
Up Session Num	Number of active SBFD sessions.
SBFD session (xxx)	Path to be detected by the SBFD session: · MPLS LSP. · SRv6 TE policy. (This field is not supported in the current software version.) · IPv6—IPv6 link.
Local Discr	Local discriminator of the session.
Remote Discr	Remote discriminator of the session.
Source IP	Source IP address of the session.
Destination IP	Destination IP address of the session.
Session State	Session state: Down or Up.
Hold Time	Length of time before the session detection timer expires, in milliseconds. For an SBFD session in Down state, this field displays 0ms.
Min Tx Inter	Minimum SBFD packet transmission interval.
Act Tx Inter	Actual SBFD packet transmission interval.
Detect Inter	Actual session detection timer.
Running Up for	Duration of the session in up state, in hh:mm:ss format. · hh—Represents the hours. · mm—Represents the minutes. · ss—Represents the seconds.
Rx Count	Number of packets received.
Tx Count	Number of packets sent.
Slot	Slot number of the card where the BFD session resides.
Color	This field is not supported in the current software version. Color attribute of the SRv6 TE policy.
NID	Forwarding entry index of the SID list. This field is displayed only when the index exists and is a non-zero value.
Diag Info	Diagnostic information about the session: · No Diagnostic. · Control Detection Time Expired—The SBFD session goes down because local detection times out. · Neighbor Signaled Session Down—The remote end notifies the local end of SBFD session down. · Concatenated Path Down—The SBFD session goes down because the concatenated path associated with the session fails.
Template Name	Template associated with the session. If no template is associated, this field is not displayed.

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# Display brief information about all SBFD sessions for the reflector.

<Sysname> display sbfd session reflector

Local discriminator 1000001 on slot 0

Configured mode: Explicit value

Total Session Num: 1

Local Discr: 1000001 Remote Discr: 1

Source IP: 2.2.2.1

Destination IP: 1.1.1.1

Hold Time: 2200ms

VRF Name: vpn1

Table 9 Command output

Field	Description
Configured mode	Discriminator type: · IP Address—IPv4 address. · Explicit Value—Integer.
Total Session Num	Total number of SBFD sessions.
Local Discr	Local discriminator of the session.
Remote Discr	Remote discriminator of the session.
Source IP	Source IP address of the session.
Destination IP	Destination IP address of the session.
Hold Time	Length of time before the session detection timer expires, in milliseconds. For an SBFD session in Down state, this field displays 0ms.
VRF Name	VPN instance bound to the interface where the packets of the SBFD session are received. If no VPN instance is bound to the interface, this field displays a hyphen (-).

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# Display detailed information about the SBFD session with local discriminator 1000001 for the reflector.

<Sysname> display sbfd session reflector discriminator 1000001

Local discriminator 1000001 on slot 0

Configured mode: IP Address

Total Session Num: 2

Local Discr: 1000001 Remote Discr: 1

Source IP: 2.2.2.1 Destination IP: 1.1.1.1

Min Tx Inter: 500ms Min Rx Inter: 10ms

Detect Multi: 5 Running Up for: 00:02:30

Rx Count: 100 Tx Count: 100

Max Rx Period: 498ms Max Tx Period: 1280us

Hold Time: 2200ms

VRF Name: vpn1

Local Discr: 1000001 Remote Discr: 2

Source IP: 2.2.2.2 Destination IP: 1.1.1.2

Min Tx Inter: 1000ms Min Rx Inter: 3790ms

Detect Multi: 5 Running Up for: 00:10:59

Rx Count: 123 Tx Count: 122

Max Rx Period: 980ms Max Tx Period: 580us

Hold Time: 2500ms

VRF Name: vpn2

Table 10 Command output

Field	Description
Configured mode	Discriminator type: · IP Address—IPv4 address. · Explicit Value—Integer.
Total Session Num	Total number of SBFD sessions.
Local Discr	Local discriminator of the session.
Remote Discr	Remote discriminator of the session.
Source IP	Source IP address of the session.
Destination IP	Destination IP address of the session.
Hold Time	Length of time before the session detection timer expires, in milliseconds. For an SBFD session in Down state, this field displays 0ms.
Min Tx Inter	Minimum transmission interval of incoming SBFD packets.
Min Rx Inter	Minimum SBFD packet receiving interval.
Detect Multi	Session detection time multiplier carried in incoming SBFD packets.
Running Up for	Duration of the session in up state, in hh:mm:ss format. · hh—Represents the hours. · mm—Represents the minutes. · ss—Represents the seconds.
Rx Count	Number of packets received.
Tx Count	Number of packets sent.
Max Rx Period	Maximum SBFD packet receiving interval in milliseconds.
Max Tx Period	Maximum response packet transmission interval, in microseconds.
Hold Time	Length of time before the session detection timer expires, in milliseconds. For an SBFD session in Down state, this field displays 0ms.
VRF Name	VPN instance bound to the interface where the packets of the SBFD session are received. If no VPN instance is bound to the interface, this field displays a hyphen (-).

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Related commands

sbfd local-discriminator

sbfd destination ipv4 remote-discriminator

Use sbfd destination ipv4 remote-discriminator to associate the destination IPv4 address of the detected path with the remote discriminator of the SBFD session for the initiator.

Use undo sbfd destination ipv4 to cancel the association between the destination IPv4 address of the detected path and the remote discriminator of the SBFD session for the initiator.

Syntax

sbfd destination ipv4 destination-ipv4-address remote-discriminator { ipv4-address | integer-value }

undo sbfd destination ipv4 destination-ipv4-address

Default

The destination IPv4 address of the detected path is not associated with the remote discriminator of the SBFD session for the initiator.

Views

System view

Predefined user roles

network-admin

Parameters

destination-ipv4-address: Specifies a valid unicast IPv4 address as the destination IPv4 address of the detected path.

ipv4-address: Specifies a valid unicast IPv4 address as the remote discriminator.

integer-value: Specifies an integer as the remote discriminator. The value range for this argument is 1 to 4294967295.

Usage guidelines

This command allows you to use the specified remote discriminator for an SBFD session to detect an LSP or MPLS TE tunnel.

The initiator selects a remote discriminator for an SBFD session as follows:

1. Selects the remote discriminator of the SBFD session used for path connectivity detection. For example, the remote discriminator of the SBFD session specified in the mpls sbfd command.

2. Selects the remote discriminator specified in this command.

3. Selects the destination IPv4 address of the detected path.

You can execute this command repeatedly to configure multiple associations between destination IPv4 addresses and remote discriminators for the initiator.

When configuring or canceling an association, the SBFD session might flap if it is in up state.

Examples

# Associate destination IPv4 address 22.22.2.2/32 of the detected LSP with remote discriminator 1.1.1.1 of the SBFD session for the initiator.

<Sysname> system-view

[Sysname] mpls bfd enable

[Sysname] mpls sbfd 22.22.2.2 32

[Sysname] sbfd destination ipv4 22.22.2.2 remote-discriminator 1.1.1.1

Related commands

mpls bfd (MPLS Command Reference)

sbfd local-discriminator

Use sbfd local-discriminator to set the local discriminator for the reflector.

Use undo sbfd local-discriminator to remove the local discriminator setting for the reflector.

Syntax

sbfd local-discriminator { ipv4-address | integer-value }

undo sbfd local-discriminator { ipv4-address | integer-value }

Default

No local discriminator is set for the reflector.

Views

System view

Predefined user roles

network-admin

Parameters

ipv4-address: Specifies a valid unicast IPv4 address as the local discriminator.

integer-value: Specifies an integer as the local discriminator. The value range for this argument is 1000001 to 4294967295.

Usage guidelines

In a BFD session, both ends periodically send BFD packets to detect bidirectional forwarding path failures. SBFD is a unidirectional failure detection mechanism that provides shorter detection time than BFD. SBFD is used in scenarios where only one end of a link requires failure detection, such as MPLS TE tunnel establishment through static SRLSP.

An SBFD session involves the following roles:

· Initiator—Periodically sends SBFD control packets to detect connectivity to remote entities. An initiator initiates SBFD sessions and maintain SBFD session state.

· Reflector—Listens for incoming SBFD control packets on local entities and replies with response SBFD control packets.

The remote discriminator in SBFD control packets sent by the initiator must be specified in the sbfd local-discriminator command. Otherwise, the reflector does not reply with response SBFD control packets.

You can execute this command multiple times to configure multiple local discriminators.

A node can act as the initiator of one session and the reflector of another session at the same time.

Examples

# Specify 1.1.1.1 as the local discriminator for the reflector.

<Sysname> system-view

[Sysname] sbfd local-discriminator 1.1.1.1

# Specify 1000001 as the local discriminator for the reflector.

<Sysname> system-view

[Sysname] sbfd local-discriminator 1000001

Related commands

display sbfd session

mpls bfd (MPLS Command Reference)

sbfd initiator accept-down-response

Use sbfd initiator accept-down-response to enable the initiator to send SBFD packets in up state upon receiving SBFD packets in down state from the reflector during session establishment.

Use undo sbfd initiator accept-down-response to restore the default.

Syntax

sbfd initiator accept-down-response

undo sbfd initiator accept-down-response

Default

During session establishment, upon receiving an SBFD packet in down state from the reflector, the initiator drops the packet. The SBFD session cannot be established.

Views

System view

Predefined user roles

network-admin

Usage guidelines

Typically, to establish an SBFD session, the initiator first sends a SBFD packet in down state. If the reflector replies with an SBFD packet in down state, the initiator will drop the packet, and the SBFD session cannot be established. To resolve this issue, configure this command on the initiator. After configuration, when the initiator receives an SBFD packet in down state from the reflector, it sends an SBFD packet in up state for successful session establishment.

Examples

# Enable the initiator to send SBFD packets in up state upon receiving SBFD packets in down state from the reflector during session establishment.

<Sysname> system-view

[Sysname] sbfd initiator accept-down-response

sbfd source-ipv6

Use sbfd source-ipv6 to specify the source IPv6 address used by the initiator to send SBFD control packets.

Use undo sbfd source-ipv6 to restore the default.

Syntax

sbfd source-ipv6 ipv6-address

undo sbfd source-ipv6

Default

No source IPv6 address is specified for SBFD control packets.

Views

System view

Predefined user roles

network-admin

Parameters

ipv6-address: Specifies a unicast IPv6 address. You can specify a site-local address for this argument.

Usage guidelines

Examples

# Specify 80::2 as the source IPv6 address for SBFD control packets.

<Sysname> system-view

[Sysname] sbfd source-ipv6 80::2

20-High Availability Command Reference

BFD commands

bfd multi-hop destination-port

Application scenarios

Operating mechanism

Recommended configuration

Restrictions and guidelines

reset bfd session statistics

snmp-agent trap enable bfd

sbfd initiator accept-down-response

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