Use bfd detect-multiplier to set the single-hop detection time multiplier for control packet mode and the detection time multiplier for 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 for control packet mode and the detection time multiplier for echo packet mode are both 5.

Views

Interface view

BFD template view

Static BFD session view

Predefined user roles

network-admin

Parameters

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)

‌

This command takes effect only on static BFD sessions for single-hop detection with control packets or echo packets.

Examples

# Set the single-hop detection time multiplier for control packet mode and the detection time multiplier for 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-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-control-interval

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

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

Syntax

bfd min-control-interval interval

undo bfd min-control-interval

Default

The minimum interval for transmitting and receiving single-hop BFD control packets is 400 milliseconds.

Views

Interface view

BFD template view

Predefined user roles

network-admin

Parameters

interval: Specifies the minimum interval for transmitting and receiving single-hop BFD control packets, in milliseconds. The value range for this argument is 3 to 1000.

Usage guidelines

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

The actual BFD 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.

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.

Examples

# Set the minimum interval for transmitting and 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-control-interval 500

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.

This command takes effect only on static BFD sessions for single-hop detection with control packets or echo packets.

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 multi-hop detect-multiplier

Use bfd multi-hop detect-multiplier to set the multihop detection time multiplier for control 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 packet mode is 5.

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 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)

This command takes effect only on static BFD sessions for multihop detection with control packets or echo packets.

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-control-interval

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

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

Syntax

bfd multi-hop min-control-interval interval

undo bfd multi-hop min-control-interval

Default

The minimum interval for transmitting and receiving multihop BFD control packets is 400 milliseconds.

Views

Interface view

Predefined user roles

network-admin

Parameters

interval: Specifies the minimum interval for transmitting and receiving multihop BFD control packets, in milliseconds. The value range for this argument is 3 to 1000.

Usage guidelines

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

The actual BFD 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.

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.

Examples

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

<Sysname> system-view

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

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.

This command takes effect only on static BFD sessions for multihop detection with echo packets.

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

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 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 an IPv6 address of the local end.

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 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

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.
IPv4 session working in control packet 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

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

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

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

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.
IPv4 session working in control packet 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.
Tracked interface	Interface monitored by the static BFD session.

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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

10-High Availability Command Reference

BFD commands

bfd multi-hop detect-multiplier

display bfd ttl

snmp-agent trap enable bfd

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