Configuring SBFD for SRv6 TE Policy

This section describes how to configure seamless bidirectional forwarding detection (SBFD) for SRv6 TE Policy.

Usage Scenario

SBFD for SRv6 TE Policy can quickly detect segment list faults. If all the segment lists of a candidate path are faulty, SBFD triggers a hot-standby candidate path switchover to minimize the impact on services.

Pre-configuration Tasks

Before configuring SBFD for SRv6 TE Policy, complete the following tasks:

Configure an SRv6 TE Policy.
Run the te ipv6-router-id ipv6Addr command to configure a global TE IPv6 router ID.

Procedure

Configure an SBFD initiator.
1. Run system-view
  The system view is displayed.
2. Run bfd
  BFD is enabled globally.
  
  BFD-related configuration can be performed only after BFD is enabled globally using the bfd command.
3. Run quit
  Return to the system view.
4. Run sbfd
  SBFD is enabled globally, and the SBFD view is displayed.
5. Run destination ipv6 ipv6-address remote-discriminator discriminator-value
  The mapping between the IPv6 address and discriminator of the SBFD reflector is configured.
  
  The IPv6 address of the SBFD reflector must be the same as the endpoint of the corresponding SRv6 TE Policy.
6. Run quit
  Return to the system view.
7. Run segment-routing ipv6
  The SRv6 view is displayed.
8. Configure SBFD for SRv6 TE Policy.
  SBFD for SRv6 TE Policy supports both global configuration and single-policy configuration. You can select either of the two modes.
  - Global configuration
    1. Run srv6-te-policy bfd seamless enable
      
      SBFD is enabled for all SRv6 TE Policies.
    2. (Optional) Run srv6-te-policy bfd { min-tx-interval tx-value | detect-multiplier detectmulti-value } ^*
      
      SBFD parameters are configured for the SRv6 TE Policies.
    3. (Optional) Run srv6-te-policy bfd { min-tx-interval backup-tx-value | detect-multiplier backup-detectmulti-value } ^* backup-path
      SBFD parameters are configured for the backup candidate paths of the SRv6 TE Policies.
    4. (Optional) Run srv6-te-policy bfd no-bypass
      The SBFD no-bypass function is enabled for the SRv6 TE Policies.
      
      After this function is configured, SBFD for SRv6 TE Policy packets do not transit local protection paths such as TI-LFA and TE FRR paths.
      
      In a scenario where SBFD for SRv6 TE Policy is deployed, if the segment lists of the primary candidate path all fail and a local protection path (for example, a TI-LFA or TE FRR path) exists, SBFD remains in the up state, and data traffic is switched to the TI-LFA or TE FRR path. However, the performance such as the bandwidth/latency of the TI-LFA or TE FRR path may be unstable, preventing the path from meeting the strict SLA requirements of high-value private line services. To resolve this problem, you can enable SBFD traffic to bypass local protection paths. In this way, SBFD goes down if the segment lists of the primary candidate path all fail, triggering the candidate path to also go down. As a result, traffic is switched to a backup candidate path or another SRv6 TE Policy.
  - Single-policy configuration
    1. Run srv6-te policy policy-name
      
      The SRv6 TE Policy view is displayed.
    2. Run bfd seamless enable or bfd disable
      
      SBFD is enabled or disabled for the SRv6 TE Policy.
    3. (Optional) Run bfd { min-tx-interval tx-value | detect-multiplier detectmulti-value } ^*
      
      SBFD parameters are configured for the SRv6 TE Policy.
    4. (Optional) Run bfd { min-tx-interval backup-tx-value | detect-multiplier backup-detectmulti-value } ^* backup-path
      SBFD parameters are configured for the backup candidate paths of the SRv6 TE Policy.
    5. (Optional) Run bfd { no-bypass | bypass }
      The SBFD no-bypass or bypass function is set for the SRv6 TE Policy.
      
      If you do not want the SBFD packets of the SRv6 TE Policy to transit local protection paths such as TI-LFA and TE FRR paths, select the no-bypass parameter. Otherwise, select the bypass parameter.
  If an SRv6 TE Policy has both the global configuration and the single-policy configuration, only the single-policy configuration takes effect.
9. (Optional) Run srv6-te-policy switch-delay switchDelay delete-delay deleteDelay
  Segment list switching and deletion delays are configured for SRv6 TE Policies.
10. Run commit
  The configuration is committed.
Configure an SBFD reflector.
1. Run system-view
  The system view is displayed.
2. Run bfd
  BFD is enabled globally.
  
  BFD-related configuration can be performed only after BFD is enabled globally using the bfd command.
3. Run quit
  Return to the system view.
4. Run sbfd
  SBFD is enabled globally, and the SBFD view is displayed.
5. Run reflector discriminator unsigned-integer-value
  A discriminator is configured for the SBFD reflector.
  
  You can use a 32-bit integer or an IP address as an SBFD discriminator. A device converts discriminators into a uniform form, ensuring that each discriminator is globally unique in a domain.
6. Run commit
  The configuration is committed.

Verifying the Configuration

After configuring SBFD for SRv6 TE Policy, run the display srv6-te policy [ endpoint ipv6-address color color-value | policy-name name-value ] command to check SRv6 TE Policy-specific SBFD status.