Configuring SBFD for SR-MPLS BE Tunnel

This section describes how to configure SBFD for SR-MPLS BE to detect SR-MPLS BE tunnel faults.

Usage Scenario

With SBFD for SR-MPLS BE, applications such as VPN FRR can be triggered to perform a fast traffic switching when the primary tunnel fails, minimizing the impact on services.

This configuration task applies to both common SR-MPLS BE tunnels and Flex-Algo-based SR-MPLS BE tunnels.

Pre-configuration Tasks

Before configuring SBFD for SR-MPLS BE tunnel, complete the following tasks:

Configure an SR-MPLS BE tunnel.
Run the mpls lsr-id lsr-id command to set the LSR ID, and ensure the peer to local end lsr-id address is reachable.

Procedure

Configuring an SBFD Initiator
1. Run system-view
  The system view is displayed.
2. Run bfd
  BFD is globally enabled.
  
  You can set BFD parameters only after running the bfd command to enable global BFD.
3. Run quit
  The system view is displayed.
4. Run sbfd
  SBFD is globally enabled.
5. (Optional) Run destination ipv4 ip-address remote-discriminator discriminator-value
  The mapping between the IP address and discriminator of the SBFD reflector is configured.
6. Run quit
  Return to the system view.
7. Run segment-routing
  The Segment Routing view is displayed.
8. Run seamless-bfd enable mode tunnel [ filter-policy ip-prefix ip-prefix-name | effect-sr-lsp ] ^*
  SBFD for SR-MPLS BE tunnel is enabled.
9. (Optional) Run seamless-bfd tunnel { min-rx-interval receive-interval | min-tx-interval transmit-interval | detect-multiplier multiplier-value } ^*
  SBFD parameters are set.
10. (Optional) Run seamless-bfd flex-algo exclude { flex-algo-begin [ to flex-algo-end ] } &<1-10>
  Flex-Algos that do not require SBFD session establishment are excluded.
  
  After the seamless-bfd enable command is run, SBFD sessions are established for all common SR-MPLS BE tunnels and Flex-Algo-based SR-MPLS BE tunnels. If some Flex-Algo-based SR-MPLS BE tunnels do not require SBFD session establishment, run the preceding command to exclude the corresponding Flex-Algos
11. (Optional) Configure IS-IS SBFD source addresses.
  In IS-IS multi-process scenarios, you can configure source addresses for SBFD sessions in different IS-IS processes.
  
  By default, MPLS LSR IDs are used to create SBFD sessions. During SBFD deployment, only an LSR ID can be used as the source of an SBFD session, but the source belongs to only one IS-IS process. As a result, in the multi-process scenarios, LSR ID-based host routes must be imported in route import mode. Otherwise, SBFD cannot take effect. If process isolation prevents route import, the device must support SBFD session establishment using different sources in different IS-IS processes.
  1. Run quit
    Return to the system view.
  2. Run isis [ process-id ]
    The IS-IS view is displayed.
  3. Run cost-style { wide | compatible | wide-compatible }
    The IS-IS wide metric is configured.
  4. Run segment-routing mpls
    SR-MPLS is enabled for IS-IS.
  5. Run segment-routing sbfd source-address ip-address
    An SBFD source address is configured.
12. Run commit
  The configuration is committed.
Configuring an SBFD Reflector
1. Run system-view
  The system view is displayed.
2. Run bfd
  BFD is globally enabled.
  
  You can set BFD parameters only after running the bfd command to enable global BFD.
3. Run quit
  The system view is displayed.
4. Run sbfd
  SBFD is globally enabled.
5. Run reflector discriminator { unsigned-integer-value | ip-address-value }
  A discriminator is configured for the SBFD reflector.
6. Run commit
  The configuration is committed.

Verifying the Configuration

After successfully configuring SBFD for SR-MPLS BE tunnel, run the display segment-routing seamless-bfd tunnel session [ prefix ip-address [ mask | mask-length ] ] command to check information about the SBFD session that monitors the SR-MPLS BE tunnel.