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| Title | Size | Download |
|---|---|---|
| 09-BFD commands | 175.09 KB |
bfd multi-hop authentication-mode
bfd multi-hop detect-multiplier
bfd multi-hop min-echo-receive-interval
bfd multi-hop min-receive-interval
bfd multi-hop min-transmit-interval
BFD commands
Basic BFD commands
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
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.
A static BFD session supports this command only when it is in IPv4 or IPv6 control packet mode used for single-hop detection.
BFD version 0 does not support this command. The configuration does not take effect.
Examples
# Configure VLAN-interface 11 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 vlan-interface 11
[Sysname-Vlan-interface11] 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 amount of 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 the connectivity to another system needs to be verified explicitly, a system 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, use the bfd echo enable command to enable the echo function for the device to periodically send echo packets to detect link connectivity. If the device does not receive echo packets from the peer within the detection time, 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 VLAN-interface 11.
<Sysname> system-view
[Sysname] interface vlan-interface 11
[Sysname-Vlan-interface11] bfd demand enable
Related commands
bfd echo enable
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 detect-multiplier-value
undo bfd detect-multiplier
Default
The single-hop detection time multiplier for control packet mode and echo packet mode is 5.
Views
Interface view
BFD template view
Static BFD session view
Predefined user roles
network-admin
Parameters
detect-multiplier-value: Specifies a detection time multiplier. The value range for this argument is 3 to 15.
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 VLAN-interface 11.
<Sysname> system-view
[Sysname] interface vlan-interface 11
[Sysname-Vlan-interface11] 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
Static BFD session 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 control-mode BFD sessions established with IPv6 link-local addresses.
A static BFD session supports this command only when it is in IPv4 or IPv6 control packet mode used for single-hop detection.
BFD version 0 does not support this command. The configuration does not take effect.
Examples
# Enable the echo function on VLAN-interface 11.
<Sysname> system-view
[Sysname] interface vlan-interface 11
[Sysname-Vlan-interface11] 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
The source IP 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 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.
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 400 milliseconds.
Views
Interface view
Static BFD session 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 100 to 1000.
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 packet 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 VLAN-interface 11.
<Sysname> system-view
[Sysname] interface vlan-interface 11
[Sysname-Vlan-interface11] 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 single-hop BFD control packets is 400 milliseconds.
Views
Interface view
BFD template view
Static BFD session view
Predefined user roles
network-admin
Parameters
interval: Specifies the minimum interval for receiving single-hop BFD control packets, in milliseconds. The value range is 100 to 1000.
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 VLAN-interface 11.
<Sysname> system-view
[Sysname] interface vlan-interface 11
[Sysname-Vlan-interface11] 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 transmitting single-hop BFD control packets is 400 milliseconds.
Views
Interface view
BFD template view
Static BFD session view
Predefined user roles
network-admin
Parameters
interval: Specifies the minimum interval for transmitting single-hop BFD control packets, in milliseconds. The value range is 100 to 1000.
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 VLAN-interface 11.
<Sysname> system-view
[Sysname] interface vlan-interface 11
[Sysname-Vlan-interface11] 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
Related commands
bfd static
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 detect-multiplier-value
undo bfd multi-hop detect-multiplier
Default
The multihop detection time multiplier for control packet mode and echo packet mode is 5.
Views
System view
Static BFD session view
Predefined user roles
network-admin
Parameters
detect-multiplier-value: Specifies the multihop detection time multiplier. The value range for this argument is 3 to 15.
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.
<Sysname> system-view
[Sysname] bfd multi-hop detect-multiplier 6
Related commands
bfd static
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 400 milliseconds.
Views
System view
Static BFD session view
Predefined user roles
network-admin
Parameters
interval: Specifies the minimum interval for receiving multihop BFD echo packets, in milliseconds. The value for this argument takes 0 or is in the range of 100 to 1000.
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 400 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. The value range is 100 to 1000.
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
Related commands
bfd static
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 400 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. The value range is 100 to 1000.
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
Related commands
bfd static
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 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
For IPv4 single-hop detection with control packets:
bfd static session-name [ peer-ip ipv4-address interface interface-type interface-number source-ip ipv4-address [ discriminator local local-value remote remote-value ] ]
For IPv4 multihop detection with control packets:
bfd static session-name [ peer-ip ipv4-address [ vpn-instance vpn-instance-name ] source-ip ipv4-address [ discriminator { auto | local local-value remote remote-value } ] [ track-interface interface-type interface-number ] ]
For IPv4 single-hop detection with 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 | local local-value } ] ]
For IPv4 multihop detection with 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 | local local-value } ] ]
For IPv6 single-hop detection with control packets:
bfd static session-name [ peer-ipv6 ipv6-address interface interface-type interface-number source-ipv6 ipv6-address[ discriminator { auto | local local-value remote remote-value } ] ]
For IPv6 multihop detection with control packets:
bfd static session-name [ peer-ipv6 ipv6-address [ vpn-instance vpn-instance-name ] source-ipv6 ipv6-address [ discriminator { auto | local local-value remote remote-value } ] [ track-interface interface-type interface-number ] ]
For IPv6 single-hop detection with 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 | local local-value } ] ]
For IPv6 multihop detection with 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 | local local-value } ] ]
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. The peer IPv4 address and the source IPv4 address determine the path to be detected.
peer-ipv6 ipv6-address: Specifies the peer IPv6 address. The peer IPv6 address and the source IPv6 address determine the path to be detected.
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 IPv4 destination address for echo packets, in dotted decimal notation. The IPv4 destination address must be a valid unicast IPv4 address of the local device.
destination-ipv6 ipv6-address: Specifies the IPv6 destination address for echo packets. The IPv6 destination address must be the IP address of the local device.
one-arm-echo: Specifies the echo packet mode for the static BFD session.
source-ip ipv4-address: Specifies the source IPv4 address for control packets, in dotted decimal notation. It must be a valid unicast IPv4 address.
peer-ipv6 ipv6-address: Specifies the source IPv6 address for control packets.
discriminator: Specifies BFD session discriminators.
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.
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 an interface, the static BFD session does not monitor any interfaces.
Usage guidelines
A static BFD session can be used for single-hop detection and multihop detection. By working with Track, a static BFD session can provide fast failure detection. For more information about Track association with BFD, see Track in High Availability Configuration Guide.
The BFD session discriminators must match on the local and peer devices. For example, if you configure bfd static abc peer-ip 20.1.1.1 vpn-instance vpn1 source-ip 20.1.1.2 discriminator local 513 remote 514 on the local device, you must configure bfd static bcd peer-ip 20.1.1.2 vpn-instance vpn1 source-ip 20.1.1.1 discriminator local 514 remote 513 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.
If you do not specify the local discriminator or remote discriminator when creating a static BFD session, you must perform either of the following tasks for the BFD session to take effect:
· Use the discriminator command to specify the local discriminator and remote discriminator for the static BFD session.
· Execute the undo bfd static command and then execute the bfd static command to re-create the static BFD session with the local and remote discriminators specified.
The bfd static session-name command without any parameters specified can only be used to enter the view of an existing static BFD session.
If you use a static BFD session in control packet mode to perform single-hop detection, make sure the following requirements are met for the BFD session to be successfully established:
· The IP address of the peer interface where the static BFD session resides is used as the peer IP address.
· The IP address of the local interface where the static BFD session resides is used as the source IP address.
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.
A static BFD session can monitor the following interfaces:
· Layer 2 Ethernet interfaces.
· Layer 3 Ethernet interfaces and their subinterfaces.
· Layer 2 aggregate interfaces and their member ports.
· Layer 3 aggregate interfaces and their subinterfaces and member ports.
Examples
# Create a static BFD session and enter its view. The static BFD session detects the link with the outgoing interface VLAN-interface 10 and the next hop 1.1.1.2. The source IP address for the session is 1.1.1.1, 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 vlan-interface 10 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 VLAN-interface 10 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 vlan-interface 11 destination-ip 1.1.1.2 source-ip 9.9.9.9 one-arm-echo discriminator auto
[Sysname-bfd-static-session-abc]
Related commands
discriminator
track bfd
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 third-party device, 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 discriminator 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 local-value | static session-name | verbose ]
display bfd session [ [ dynamic ] [ control | echo ] [ ip ] [ state { down | admin-down | init | up } ] [ discriminator remote remote-value ] [ peer-ip ipv4-address [ vpn-instance vpn-instance-name ] ] [ verbose ] ]
display bfd session [ [ dynamic ] [ control | echo ] [ ipv6 ] [ state { down | admin-down | init | up } ] [ discriminator remote remote-value ] [ peer-ipv6 ipv6-address [ vpn-instance vpn-instance-name ] ] [ verbose ] ]
display bfd session [ [ static ] [ ip ] [ state { down | admin-down | init | up } ] [ discriminator remote remote-value ] [ peer-ip ipv4-address [ vpn-instance vpn-instance-name ] ] [ verbose ]
display bfd session [ [ static ] [ ipv6 ] [ state { down | admin-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 local-value: Specifies a BFD session by its local discriminator. The value range for the local-value argument is 1 to 4294967295.
static session-name: Specifies a static BFD session by its name, a case-sensitive string of 1 to 64 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.
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.
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.
Usage guidelines
If you do not specify the dynamic or static keyword, this command displays all dynamic and static BFD sessions.
Examples
# Display brief information about all BFD sessions.
<Sysname> display bfd session
Total sessions: 4 Up sessions: 4 Init mode: Active
IPv4 session working in control packet mode:
LD/RD SourceAddr DestAddr State Holdtime Interface
513/513 1.1.1.1 1.1.1.2 Up 2297ms Vlan100
IPv6 session working in control packet 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: Vlan100
Hold time: 2142ms
IPv4 static session working in control packet mode:
LD/RD SourceAddr DestAddr State Holdtime Interface
1600/1600 1.1.1.1 1.1.1.2 Up 2290ms Vlan100
IPv6 static session working in control packet mode:
Local discr: 1700 Remote discr: 1700
Source IP: FE80::20C:29FF:FED4:7171
Destination IP: FE80::20C:29FF:FE72:AC4D
Session state: Up Interface: Vlan100
Hold time: 2142ms
|
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 packet mode. · IPv4 session working in echo mode. · IPv6 session working in control packet mode. · IPv6 session working in echo mode. · IPv4 static session working in control packet mode. · IPv6 static session working in control packet mode. |
|
LD/RD |
Local discriminator/Remote discriminator of the session. |
|
SourceAddr |
Source IP address of the session. |
|
DestAddr |
Destination IP address of the session. |
|
Session State/State |
Session state: Down, Init, or Up. |
|
Interface |
Name of the interface of the session. |
|
Hold Time/Holdtime |
Length of time before the session detection timer expires, in milliseconds. For a BFD session in Down state, this field displays 0ms. |
|
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. |
# Display detailed BFD session information.
<Sysname> display bfd session verbose
Total sessions: 4 Up sessions: 4 Init mode: Active
IPv4 session working in control packet 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: Vlan-interface100
Min Tx interval: 500ms Actual Tx interval: 500ms
Min Rx interval: 500ms Detection time: 2500ms
Rx count: 42 Tx count: 43
Connection type: Direct Up duration: 00:00:20
Hold time: 2078ms Auth mode: None
Detect mode: Async Slot: 0
Protocol: OSPF
Version:1
Diag info: No Diagnostic
Hardware mode: Disable
Tracked interface: Vlan-interface100
IPv6 session working in control packet 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: Vlan-interface100
Min Tx interval: 500ms Actual Tx interval: 500ms
Min Rx interval: 500ms Detection time: 2500ms
Rx count: 38 Tx count: 38
Connection type: Direct Up duration: 00:00:15
Hold time: 2211ms Auth mode: None
Detection mode: Async Slot: 0
Protocol: OSPFv3
Version: 1
Diag info: No Diagnostic
Hardware mode: Disable
IPv4 static session working in control packet mode:
Session name: aaaa
Local discr: 1600 Remote discr: 1600
Source IP: 1.1.1.1 Destination IP: 1.1.1.2
Destination port: 3784 Session state: Up
Interface: Vlan-interface100
Min Tx interval: 500ms Actual Tx interval: 500ms
Min Rx interval: 500ms Detection time: 2500ms
Rx count: 42 Tx count: 43
Connection type: Direct Up duration: 00:00:20
Hold time: 2078ms Auth mode: None
Detection mode: Async Slot: 0
Protocol: STATIC_IPv4
Version: 1
Diag info: No Diagnostic
Hardware mode: Disable
IPv6 static session working in control packet 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: Vlan-interface100
Min Tx interval: 500ms Actual Tx interval: 500ms
Min Rx interval: 500ms Detection time: 2500ms
Rx count: 38 Tx count: 38
Connection type: Direct Up duration: 00:00:15
Hold time: 2211ms Auth mode: None
Detection mode: Async Slot: 0
Protocol: STATIC_IPv6
Version: 1
Diag info: No Diagnostic
Hardware mode: Disable
Table 4 Command output
|
Field |
Description |
|
Total sessions |
Total number of BFD sessions. |
|
Up sessions |
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 packet mode. · IPv4 session working in echo mode. · IPv6 session working in control packet mode. · IPv6 session working in echo mode. · IPv4 static session working in control packet mode. · IPv6 static session working in control packet mode. |
|
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, AdmDown, Init, or Up. |
|
Interface |
Name of the interface of the session. |
|
Min Tx interval |
Minimum transmit interval. |
|
Min Rx interval |
Minimum receive interval. |
|
Actual Tx interval |
Actual transmit interval. |
|
Detection time |
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. For a BFD session in down state, this field displays 0ms. |
|
Auth mode |
Session authentication mode. |
|
Connection type |
Connection type of the interface: Direct or Indirect. |
|
Up duration |
Time period for which the session has been up. |
|
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. Slot number of the card where the BFD session resides. |
|
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. · STATIC4—IPv4 static routing. · TRACK—Track. · RIP. · IPFRR—FIB IP FRR. · MAD. · OSPFv3. · BGP4+. · PIM. · PIM6—IPv6 PIM. · STATIC6—IPv6 static routing. · RIPNG—RIPng. · Interface—Interface state. · TUNNEL. · LAGG—Link aggregation. · STATIC_IPv4—IPv4 static BFD session. · STATIC_IPv6—IPv6 static BFD session. |
|
TTL |
TTL value of BFD packets. |
|
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. |
|
Hardware mode |
Whether BFD packets are processed in hardware: · Enabled. · Disable—BFD packets are processed in software. |
|
Tracked interface |
Interface monitored by the static BFD session. |
Related commands
bfd static
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
