Configuring VPN GR Helper

Context

In Graceful Restart (GR) process, two roles are defined according to their functions, that is, GR restarter and GR helper.

GR restarter: performs active/standby control board switchover or the system upgrade.
GR helper: helps the GR restarter to implement uninterrupted service forwarding.

VPN GR is the collection of GR capabilities of various protocols running on devices on VPN networks. You need to configure IGP GR helper, MPLS LDP GR helper, MPLS TE GR helper, or BGP GR helper on neighboring devices of the GR restarter based on the related protocol running on the GR restarter.

Configure specified VPN GR on the PE, CE, and P as follows:

Configure IGP GR helper, MPLS LDP GR helper, MPLS TE GR helper, or BGP GR helper on the PE device.
Configure MPLS LDP GR helper, MPLS TE GR helper, or IGP GR helper on the P device.
Configure IGP GR helper or BGP GR helper on the CE device.
If a VPN spans multiple ASs, you must configure IGP GR helper, MPLS LDP GR helper, MPLS TE GR helper, or BGP GR helper on the ASBR.

Pre-configuration Tasks

Before configuring VPN GR helper, complete the following tasks:

Configure basic BGP/MPLS IP VPN functions. For details, see Configuring Basic BGP/MPLS IP VPN Functions.
Enable GR capability on all the devices on the network.

Procedure

Configure IS-IS GR helper or OSPF GR helper.
- For details about how to configure IS-IS GR helper, see Enabling IS-IS GR in "IPv4 IS-IS Configuration" in the S2720, S5700, and S6700 V200R019C10 Configuration Guide - IP Unicast Routing.
- For details about how to configure OSPF GR helper, see (Optional) Configuring GR Session Parameters on the Helper in "OSPF Configuration" in the S2720, S5700, and S6700 V200R019C10 Configuration Guide - IP Unicast Routing.
Configure BGP GR helper.
- For details about how to configure BGP GR helper, see Configuring BGP GR in "BGP Configuration" in the S2720, S5700, and S6700 V200R019C10 Configuration Guide - IP Unicast Routing.
Configure MPLS LDP GR helper or MPLS TE GR helper.
- For details about how to configure MPLS LDP GR helper, see Configuring LDP GR in "MPLS LDP Configuration" in the S2720, S5700, and S6700 V200R019C10 Configuration Guide - MPLS.
- For details about how to configure MPLS TE GR helper, see Configuring RSVP GR in "MPLS TE Configuration" in the S2720, S5700, and S6700 V200R019C10 Configuration Guide - MPLS.