Configuring IP+VPNv4 Hybrid FRR

This section describes how to configure IP+VPNv4 hybrid FRR. On a network where a CE is dual-homed to two PEs, if the link between the master PE and the CE is unreachable, the master PE switches traffic to the link between the backup PE and the CE for transmission. IP+VPNv4 hybrid FRR improves network reliability.

Usage Scenario

IP+VPNv4 hybrid FRR can quickly switch traffic from a PE to another PE that serves as the backup next hop if the primary route to a CE is unreachable.

A PE learns VPN routes with the same prefix from a CE and other PEs. In this situation, IP+VPNv4 hybrid FRR can be configured on the PE. After being enabled with IP+VPNv4 hybrid FRR, the PE generates a primary route and a backup route to the VPN prefix. If the link between the PE and CE fails, the traffic quickly switches to the backup next hop (backup PE).

On the network shown in Figure 1, in normal situations, PE1 selects Link_A to forward traffic to the CE and uses Link_B as the backup link. If PE2 detects that the route to the CE is unreachable, it will immediately switch traffic to Link_B and private network routes will be converged. This implementation minimizes the impact on VPN services.

Figure 1 IP+VPNv4 hybrid FRR

At present, the NetEngine 8000 F supports the following IP+VPNv4 hybrid FRR modes:

Private network IP FRR: applies to the networking where a non-BGP routing protocol runs between the PEs and CE.
Private network BGP auto FRR: applies to the networking where BGP runs between the PEs and CE.

Pre-configuration Tasks

Before configuring IP+VPNv4 hybrid FRR, complete the following tasks:

Configure a BGP/MPLS IP VPN.
Configure a PE to learn IP routes with the same prefix from a CE and other VPNv4 peers.

Procedure

Configure private network IP FRR.
1. Run system-view
  The system view is displayed.
2. Run ip vpn-instance vpn-instance-name
  The VPN instance view is displayed.
3. Run ipv4-family
  The VPN instance IPv4 address family view is displayed.
4. Run ip frr
  Private network IP FRR is enabled.
5. Run commit
  The configuration is committed.
Configure private network BGP auto FRR.
1. Run system-view
  The system view is displayed.
2. Run bgp as-number
  The BGP view is displayed.
3. Run ipv4-family vpn-instance vpn-instance-name
  The BGP-VPN instance IPv4 address family view is displayed.
4. Run auto-frr
  Private network BGP auto FRR is enabled.
5. (Optional) Run route-select delay delay-value
  A delay for selecting a route to the intermediate device on the primary path is configured. After the primary path recovers, an appropriate delay ensures that traffic switches back to the primary path after the intermediate device completes refreshing forwarding entries.
6. Run commit
  The configuration is committed.