Enabling MPLS TE FRR and Configuring Attributes for an Automatic Bypass LSP

Procedure

1. Run system-view

   The system view is displayed.

2. Run interface tunnel tunnel-number

   The tunnel interface view of the primary LSP is displayed.

3. Run mpls te fast-reroute [ bandwidth ]

   TE FRR is enabled.

   If TE FRR bandwidth protection is needed, configure the bandwidth parameter in this command.

4. (Optional) Run mpls te frr-switch degrade

   The MPLS TE tunnel is enabled to mask the FRR function, preventing traffic from being switched to the primary LSP in the FRR-in-use state.

   After TE FRR takes effect, traffic is switched to the bypass LSP when the primary LSP fails. If the bypass LSP is not the optimal path, traffic congestion easily occurs. To prevent traffic congestion, you can configure LDP to protect TE tunnels. To have the LDP protection function take effect, you also need to run the mpls te frr-switch degrade command to enable the MPLS TE tunnel to mask the FRR function. After the command is run:

   1. If the primary LSP is in the FRR-in-use state (that is, traffic has been switched to the bypass LSP), traffic cannot be switched to the primary LSP.

   2. If HSB is configured for the tunnel and an HSB LSP is available, traffic is switched to the HSB LSP.

   3. If no HSB LSP is available for the tunnel, the tunnel is unavailable, and traffic is switched to LDP tunnels.

   4. If no LDP tunnels are available, traffic is interrupted.

5. (Optional) Run mpls te bypass-attributes [ bandwidth bandwidth | priority setup-priority [ hold-priority ] ]

   Attributes are set for the automatic bypass LSP.

   

   • The bandwidth attribute can be set for the bypass LSP only after the mpls te fast-reroute bandwidth command is run for the primary LSP.

   • The bypass LSP bandwidth cannot exceed the primary LSP bandwidth.

   • If no attributes are configured for an automatic bypass LSP, the automatic bypass LSP uses the same bandwidth as that of the primary LSP by default.

   • The setup priority of a bypass LSP must be lower than or equal to the holding priority. These priorities cannot be higher than the corresponding priorities of the primary LSP.

   • If FRR is disabled, the bypass LSP attributes are automatically deleted.

6. Run quit

   Return to the system view.

7. Run interface interface-type interface-number

   The interface view of the link through which the primary LSP passes is displayed.

8. (Optional) Run mpls te auto-frr attributes { bandwidth bandwidth | priority setup-priority [ hold-priority ] | hop-limit hop-limit-value }

   An Attribute is configured for the bypass LSP.

9. Run quit

   Return to the system view.

10. (Optional) Configure affinities for the automatic bypass tunnel.

    An affinity determines attributes for links to be used by an automatic bypass LSP. The affinity and the link administrative group attribute together are used to determine which links the automatic bypass LSP uses.

    An affinity can be set using either a hexadecimal number or a name.

    • Set a hexadecimal number.

      1. Run interface interface-type interface-number

         The interface view of the link through which the bypass LSP passes is displayed.

      2. Run mpls te link administrative group value

         An administrative group attribute is specified.

      3. (Optional) Run mpls te auto-frr attributes affinity property properties [ mask mask-value ] or mpls te auto-frr attributes affinity { include-all | include-any | exclude } bit-name &<1-32>

         An affinity for a bypass LSP is configured.

      4. Run quit

         Return to the system view.

      5. Run interface tunnel tunnel-number

         The tunnel interface view of the primary LSP is displayed.

      6. Run mpls te bypass-attributes affinity property properties [ mask mask-value]

    • Set an affinity name.

      Naming an affinity makes the affinity easy to understand and maintain. Setting an affinity name is recommended.

      1. Run path-constraint affinity-mapping

         An affinity name template is configured, and the template view is displayed.

         This template must be configured on each node that is used to calculate the path over which an automatic bypass LSP is established. The mappings between affinity names and bits on each node must be consistent globally.

      2. Run attribute affinity-name bit-sequence bit-number

         A mapping between an affinity bit and name is configured.

         The affinity attribute contains 128 bits. You can run this command repeatedly to configure all or only some bits.

      3. Run quit

         Return to the system view.

      4. Run interface interface-type interface-number

         The interface view of the link through which the bypass LSP passes is displayed.

      5. Run mpls te link administrative group name bit-name &<1-32>

         An administrative group attribute is specified.

      6. Run quit

         Return to the system view.

      7. Run interface tunnel tunnel-number

         The tunnel interface view of the primary LSP is displayed.

      8. Run mpls te bypass-attributes affinity { include-all | include-any | exclude } bit-name &<1-32>

         An affinity of the bypass LSP is configured.

      

      If an automatic bypass LSP that satisfies the specified affinity cannot be established, a node will bind a manual bypass LSP satisfying the specified affinity to the primary LSP.

11. Run commit

    The configuration is committed.