Configuring RSVP GR
Pre-configuration Tasks
RSVP GR prevents service interruptions during an active/standby switchover and allows a dynamic CR-LSP to be restored.
- Configure a dynamic MPLS TE or DS TE tunnel. For details, see Configuring a Dynamic MPLS TE Tunnel or Configuring a Dynamic DS-TE Tunnel.
- Configure IS-IS GR or OSPF GR on each LSR.
NOTE:
The AR3260 can function as both the GR restarter and GR helper, and other devices can only function as the GR helper.
Enabling the RSVP Hello Extension Function
Context
By configuring the RSVP Hello extension, you can enable a device to quickly check reachability between RSVP nodes.
Perform the following configurations on a GR Helper nodes.
Procedure
- Run system-view
The system view is displayed.
- Run mpls
The MPLS view is displayed.
- Run mpls rsvp-te hello
The RSVP Hello extension function is enabled globally.
- Run quit
The system view is displayed.
- Run interface interface-type interface-number
The RSVP-TE interface view is displayed.
- Run mpls rsvp-te hello
The RSVP Hello extension function is enabled on the interface.
By default, although the RSVP Hello extension function has been enabled globally, it is disabled on RSVP-enabled interfaces.
Enabling RSVP GR
(Optional) Enabling the RSVP GR Helper Function
Context
By being enabled with RSVP GR Helper, a device supports the GR capability of its neighbor.
RSVP GR takes effect on the RSVP GR-enabled neighbor automatically after the neighbor is enabled with RSVP GR. If the GR node's neighbor is a GR node, do not perform the following configurations. If the GR node's neighbor is not a GR node, perform the following configurations.
Perform the following configurations on GR Helper nodes.
(Optional) Configuring Hello Sessions Between RSVP GR Nodes
(Optional) Modifying Basic Time
Context
After an active/standby switchover starts, an RSVP GR node has an RSVP smoothing period, during which the data plane continues forwarding data if the control plane is not restored. After RSVP smoothing is completed, a restart timer is started.
Restart timer value = Basic time + Number of ingress LSPs x 60 ms + Number of none-ingress LSPs x 15 ms
In this formula, the default basic time is 90 seconds and is configurable by using a command line, and the number of LSPs is the number of LSPs with the local node being the ingress.
After the restart timer expires, the recovery timer is started.
Recovery timer = Restart time + Total number of LSPs x 40 ms
Perform the following configurations on a GR node.