MPLS Process Restart
The MPLS process restart capability is a fault containment mechanism which ensures that process-level failures do not cause system-level failures. To achieve process restart capability, each process must run in its protected memory space independent of kernel.
The MPLS process restart performs a cold reboot
on crashing. All modules and processes that interact with MPLS adjust accordingly. All
MPLS-based services, such as IPoMPLS, VLL, and VPLS are disrupted for the duration of
MPLS process restart. Once the MPLS process is restarted, the control protocols (LDP and
RSVP) re-signal the tunnels and cross-connects and subsequently, all dependent MPLS
applications resume service.
MPLS Cold Process Restart User-Observable
Behavior
- All other non-MPLS services continue to function
normally without any disruption due to MPLS process termination.
- Traffic loss on applications using MPLS services
until the MPLS process restarts and re-signaling are complete. VLL/VPLS and BGP
IPoMPLS services are affected during MPLS process restart.
- Any in progress (unacknowledged) MPLS configuration sessions will not be honored, and the user must reconfigure after the MPLS process comes back up. Attempts to configure or retrieve the operational state returns with an error.
- Once MPLS process restarts, it comes up with the previous running configuration and proceeds to establish all sessions and tunnels. The dependent MPLS services are restored.
- Existing configuration CLI sessions on MPLS process restart. Example: User was in the middle of configuring an LSP and MPLS process restarts, once MPLS is UP user can continue.
- Existing display CLI sessions with respect to MPLS are continued.
- No new MPLS configuration or display of operational information on MPLS is allowed during the time MPLS process is restarting.
- Graceful restart of LDP has no effect as the MPLS entries are cleaned up from the forwarding layer.
To following command disables the MPLS process
restart.
device# configure
device(config)# ha
device(config-ha)# no process-restart mpls
