This section describes how to configure one-arm bidirectional forwarding detection (BFD) for SRv6 TE Policy.
SBFD for SRv6 TE Policy requires you to configure the mapping between the reflector's IPv6 address and discriminator on the headend of the involved SRv6 TE Policy and configure the same reflector discriminator on the endpoint of the policy. If these requirements are not met, SBFD loopback packets cannot be constructed. In addition, you must ensure that the configured reflector discriminator is globally unique to avoid possible SBFD errors.
In inter-AS SRv6 TE Policy scenarios, the preceding constraints on the reflector discriminator make network planning inconvenient. To address this issue, the one-arm BFD for SRv6 TE Policy function is provided.
One-arm BFD for SRv6 TE Policy can quickly detect segment list faults. If all the segment lists of a candidate path are faulty, one-arm BFD triggers a hot-standby candidate path switchover to minimize the impact on services.
Before configuring one-arm BFD for SRv6 TE Policy, complete the following tasks:
Configure an SRv6 TE Policy.
Run te ipv6-router-id ipv6Addr A global TE IPv6 router ID is configured.
The system view is displayed.
BFD is enabled globally.
BFD-related configuration can be performed only after BFD is enabled globally using the bfd command.
Return to the system view.
The SRv6 view is displayed.
Run srv6-te-policy bfd unaffiliated enable
One-arm BFD is enabled for all SRv6 TE Policies.
(Optional) Run srv6-te-policy bfd { min-tx-interval tx-value | detect-multiplier detectmulti-value } *
One-arm BFD parameters are configured for the SRv6 TE Policies.
One-arm BFD parameters are configured for the backup candidate paths of the SRv6 TE Policies.
The BFD no-bypass function is enabled for the SRv6 TE Policies.
After this function is enabled, one-arm BFD for SRv6 TE Policy packets do not transit local protection paths such as TI-LFA and TE FRR paths.
Take a TE FRR scenario as an example. If the current SID is unreachable, the involved SRv6 TE Policy directly uses the next SID for forwarding. If the next SID is also unreachable, the policy uses the next-next SID for forwarding. This process repeats until the destination IPv6 address of the packet becomes the TE IPv6 router ID of the headend. In this case, BFD packets are looped back to the headend, and the BFD state remains up (inconsistent with the actual forwarding status of the SRv6 TE Policy). As such, you are advised to enable the BFD no-bypass function in one-arm BFD for SRv6 TE Policy scenarios.
Run srv6-te policy policy-name
The SRv6 TE Policy view is displayed.
Run bfd unaffiliated enable or bfd disable
One-arm BFD is enabled or disabled for the SRv6 TE Policy.
(Optional) Run bfd { min-tx-interval tx-value | detect-multiplier detectmulti-value } *
One-arm BFD parameters are configured for the SRv6 TE Policy.
One-arm BFD parameters are configured for the backup candidate paths of the SRv6 TE Policy.
The one-arm BFD no-bypass or bypass function is set for the SRv6 TE Policy.
If you do not want the one-arm BFD 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.
Segment list switching and deletion delays are configured for SRv6 TE Policies.
The configuration is committed.
After configuring one-arm BFD 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 one-arm BFD status.