(Optional) Configuring One-Label-per-Next-Hop Label Distribution
To save label resources on a PE, configure one-label-per-next-hop label distribution on the PE. Only one label is allocated to the VPNv4 routes that have the same next-hop address and outgoing label.
Context
In the scenario where multiple CEs access a PE, if the PE needs to send large numbers of VPNv4 routes to its peer but the MPLS labels are inadequate, configure one-label-per-next-hop label distribution on the PE. Then the PE allocates only one label to the VPNv4 routes that have the same next-hop address and outgoing label, which greatly saves label resources.
Perform the following steps on a PE.
Procedure
- Run system-view
The system view is displayed.
- Run ip vpn-instance vpn-instance-name
The VPN instance view is displayed.
- Run ipv4-family
The BGP-IPv4 unicast address family view is displayed.
- Run apply-label per-nexthop
One-label-per-next-hop label distribution for VPNv4 routes is enabled on the PE.
After one-label-per-next-hop label distribution is enabled or disabled, the label allocated by the PE to a route changes, which leads to a transient loss of VPN packets.
- (Optional) Run apply-label per-nexthop pop-go
The device is configured to assign a unique label to the VPNv4 routes with the same next-hop address sent to its VPNv4 peer and forward the data packets received from its VPNv4 peer through outbound interfaces found in the local ILM.
In VPN instance IPv4 address family view, the apply-label per-nexthop pop-go and apply-label per-nexthop commands are overwritten. The latest configuration overrides the previous one.
- Run commit
The configuration is committed.
Verifying the Configuration
After completing the configuration, you can run the display ip vpn-instance verbose to view details on VPN instances.