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
The mode of establishing a backup CR-LSP is configured.
By default, a tunnel is not backed up.
To implement fast switching at the millisecond level, perform the operation of Configuring Static BFD for CR-LSPs.
After hot standby 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.
By default, no explicit path is configured for a backup CR-LSP.
- (Optional) Configure
an affinity for a backup CR-LSP.
Use either of the following methods to configure an affinity for a backup CR-LSP:
Run mpls te affinity property properties [ mask mask-value ] secondary
An affinity property value is configured for a backup CR-LSP.
Run mpls te affinity secondary { include-all | include-any | exclude } bit-name &<1-32>
Affinity property names are configured for a backup CR-LSP.
Configure a mapping template for affinity names and bits before running this command, and the bit-name must be within the range defined in the template.
Affinity property of a backup CR-LSP needs to work with the link administrative group attribute to determine the link attributes to be included or excluded during link selection. For details, see Configuring Administrative Group and Affinity Property.
By default, no affinity property is configured for a backup CR-LSP.
- (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 commit
The configuration is committed.