Creating a Backup CR-LSP
Context
CR-LSP backup can be configured to allow traffic to switch from a primary CR-LSP to a backup CR-LSP, providing end-to-end protection.
Perform the following configurations on the ingress node of an MPLS TE tunnel.
Procedure
- Run system-view
The system view is displayed.
- Run interface tunnel tunnel-number
The tunnel interface view is displayed.
- Run mpls te backup hot-standby
or run mpls te backup ordinary
The mode of establishing a backup CR-LSP is configured.
If hot-standby is specified, a hot-standby CR-LSP is set up. To implement fast switching at the millisecond level, perform the operation of Configuring Static BFD for CR-LSPs or Configuring Dynamic BFD for CR-LSPs.
A tunnel interface cannot be used for both a bypass tunnel and a backup tunnel. A protection failure will occur if the mpls te backup and mpls te bypass-tunnel commands are run on the tunnel interface, or if the mpls te backup and mpls te protected-interface commands are run on the tunnel interface. For details on how to create a bypass CR-LSP, see Configuring Manual TE FRR or Configuring Auto TE FRR.
A tunnel interface cannot be used for both a bypass tunnel and a protection tunnel in a tunnel protection group. A protection failure will occur if the mpls te backup and mpls te protection tunnel commands are run on the tunnel interface. For details on how to create a protection tunnel, see Configuring a Tunnel Protection Group.
After hot standby or ordinary backup is configured, the system selects a path for a backup CR-LSP. To specify a path for a backup CR-LSP, repeatedly perform one or more of steps 4 to 6. When hot standby is configured, repeatedly perform one or more of steps 7 to 9.
- (Optional) Run mpls te path explicit-path path-name secondary
An explicit path is specified for the backup CR-LSP.
Use a separate explicit path for the backup CR-LSP to prevent the backup CR-LSP from completely overlapping its primary CR-LSP. Protection will fail if the backup CR-LSP completely overlaps its primary CR-LSP.
The mpls te path explicit-path command can be run successfully only after an explicit path is set up by running the explicit-path path-name command in the system view, and the nodes on the path are specified.
- (Optional) Run mpls te affinity property properties [ mask mask-value ] secondary
The affinity property is configured for the backup CR-LSP.
By default, the affinity property used by the backup CR-LSP is 0x0 and the mask is 0x0.
- (Optional) Run mpls te hop-limit hop-limit-value secondary
The hop limit is set for the backup CR-LSP.
The default hop limit is 32.
- (Optional) Run mpls te backup hot-standby overlap-path
The path overlapping function is configured. This function allows a hot-standby CR-LSP to use links of a primary CR-LSP.
By default, the path overlapping function is disabled. If the path overlapping function is disabled, a hot-standby CR-LSP may fail to be set up.
After the path overlapping function is configured, the path of the hot-standby CR-LSP partially overlaps the path of the primary CR-LSP when the hot-standby CR-LSP cannot exclude paths of the primary CR-LSP.
- (Optional) Run mpls te backup hot-standby wtr interval
The WTR time for a switchback is set.
By default, the WTR time for switching traffic from a hot-standby CR-LSP to a primary CR-LSP is 10 seconds.
- (Optional) Run mpls te backup hot-standby mode { revertive [ wtr interval ] | non-revertive }
A revertive mode is specified.
By default, the revertive mode is used.
- Run mpls te commit
The configuration is committed.
