Creating a Tunnel Protection Group
A configured protection tunnel can be bound to a working tunnel to form a tunnel protection group. If the working tunnel fails, traffic switches to the protection tunnel, which improves tunnel reliability.
Context
A tunnel protection group can be configured on the ingress to protect a working tunnel. The switchback delay time and a switchback mode can also be configured. If the revertive mode is used, the wait to restore (WTR) time can be set.
Procedure
- Run system-view
The system view is displayed.
- Run interface tunnel interface-number
The tunnel interface view is displayed.
- Run mpls te protection tunnel tunnel-id [ [ holdoff holdoff-time ] | [ mode { non-revertive | revertive [ wtr wtr-time ] } ] ] *
The working tunnel is added to a protection group.
The following parameters can be configured in this step:
tunnel-id specifies the ID of a protection tunnel.
holdoff-time specifies the period between the time when a signal failure occurs and the time when the protection switching algorithm is initiated upon notification of the signal fault. holdoff-time specifies a multiplier of 100 milliseconds.
Holdoff-time = 100 milliseconds x holdoff-time
In non-revertive mode, traffic does not switch back to a working tunnel even after the working tunnel recovers.
In revertive mode, traffic switches back to a working tunnel after the working tunnel recovers.
The WTR time is the time elapses before traffic switching is performed. The wtr-time parameter specifies a multiplier of 30 seconds.
WTR time = 30 seconds x wtr-time
- Run commit
The configuration is committed.
- Configure a detection mechanism.
Follow-up Procedure
You can also perform the preceding steps to modify a protection group.
An MPLS TE tunnel protection group must be detected by MPLS OAM or MPLS-TP OAM to rapidly trigger protection switching if a fault occurs.
- If both the working and protection tunnels are static bidirectional associated LSPs, configure MPLS OAM for bidirectional associated LSPs.
- If both the working and protection tunnels are static bidirectional co-routed LSPs, configure MPLS OAM for bidirectional co-routed LSPs.
- If OAM is deleted before APS is deleted, APS incorrectly considers that OAM has detected a link fault, affecting protection switching. To resolve this issue, re-configure OAM.
After an MPLS TE tunnel protection group is created, if MPLS-TP OAM is used to detect faults and both the working and protection tunnels are static bidirectional co-routed CR-LSPs, configure MPLS-TP OAM for bidirectional co-routed LSPs.