Using static BFD in echo packet mode to detect
SF reachability
About this task
Perform this task on an SFF to use a static BFD session in echo packet mode to detect the reachability of the SF associated with that SFF. When the SF is unreachable, the system can quickly trigger dualhoming protection or bypass protection for the SRv6 service chain in static proxy mode.
Restrictions and guidelines
Layer 2 encapsulation does not support this feature in the current software version.
You only need to create a static BFD session on the local SFF.
When creating a static BFD session on an SFF, you must specify the IPv4 address of the SF associated with that SFF as the peer address of the session. The system only checks the IPv4 address format and does not validate it. To ensure successful static BFD session establishment, make sure the peer IP address and source IP address are correct for the session.
The local discriminator of each static BFD session must be unique.
When creating a static BFD session, you can specify a source IPv4 address for echo packets or not.
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If you do not specify a source IPv4 address, the system uses the IPv4 address specified by using the bfd echo-source-ip command as the source IPv4 address of echo packets.
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If you specify a source IPv4 address, the system uses the specified IPv4 address as the source
IPv4 address of echo packets. As a best practice, specify a source IP address when creating a static BFD session in echo packet mode.
For more information about the commands in this section, see BFD commands in High Availability
Command Reference .
Procedure
1. Enter system view. system-view
2. Configure the source IPv4 address of echo packets.
bfd echo-source-ip ip-address
By default, no source IPv4 address is configured for echo packets.
The source IP address cannot be on the same network segment as any local interface's IP address. This avoids the peer from sending a large number of ICMP redirect packets to cause network congestion.
3. Create a static BFD session and enter static BFD session view.
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 ] ]
4. (Optional.) Specify the local discriminator for the static BFD session. discriminator local local-value
By default, no local discriminator is specified for a static BFD session.
Use this command only if no local discriminator is specified for a static BFD session when the session is created.
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