apply-label pop-go (VPN instance IPv4 address family view)

Function

The apply-label per-route pop-go command configures a device to assign labels to VPNv4 routes sent to its peer, removes such a label in a data packet received from the peer, and forward the data packet through the outbound interface found in the ILM table. With this command configuration, the device uses the per-route label allocation mode, so that it assigns a unique label to each VPNv4 route.

The undo apply-label per-route pop-go command restores the default configuration.

The apply-label per-nexthop pop-go command configures a device to assign a unique label to VPNv4 routes with the same next-hop address sent to its peer and forward the data packets received from its peer through outbound interfaces found in the ILM table after removing packet labels.

The undo apply-label per-nexthop pop-go command restores the default configuration.

By default, after a device receives a labeled data packet, the device removes the label of the data packet and forwards the packet based on a forwarding entry found in its IP forwarding table.

Format

apply-label { per-nexthop | per-route } pop-go

undo apply-label { per-nexthop | per-route } pop-go

Parameters

Parameter	Description	Value
per-nexthop	Specifies the label distribution mode in which a label is allocated to each next hop.	-
per-route	Specifies the label distribution mode in which each route is assigned a label.	-

Parameter

Description

Value

per-nexthop

Specifies the label distribution mode in which a label is allocated to each next hop.

per-route

Specifies the label distribution mode in which each route is assigned a label.

Task Name	Operations
l3vpn	write

Usage Guidelines

Usage Scenario

By default, after the local device in the BGP/MPLS VPN networking receives a labeled data packet from a VPN instance, the local device removes the label, searches the IP forwarding table for a forwarding entry according to the longest-match rule, and sends the packet based on the found forwarding entry.

After the apply-label per-route pop-go command is configured, the local device records in the ILM table the mapping between the label assigned to each VPNv4 route and the outbound interface of the route. Then, after the local device receives a labeled data packet from its BGP VPNv4 peer, the local device directly searches the ILM table for an outbound interface based on label information carried in the packet and forwards the packet through the found outbound interface after removing its label. This implementation significantly accelerates packet forwarding.

After the apply-label per-nexthop pop-go command is run, the local device records in the ILM table the mapping between the label assigned to BGP VPNv4 routes with the same next-hop address and the outbound interface of the route. After the local device receives a labeled data packet from its peer, the local device directly searches the ILM table for an outbound interface based on label information carried in the packet and forwards the packet through the found outbound interface after removing its label. This implementation significantly accelerates packet forwarding.

Prerequisites

An RD has been configured using the route-distinguisher command in the VPN instance IPv4 address family view.

Precautions

The apply-label pop-go command is mutually exclusive with the apply-label command in the VPN instance IPv4 address family. The latest configuration overrides the previous one.

After the apply-label pop-go command is run, the device removes the label, searches the ILM table for the corresponding outbound interface, and forwards the data packet, without querying the IP forwarding table. The apply-label command, however, needs the device to query the IP forwarding table for forwarding.

apply-label pop-go (VPN instance IPv4 address family view)

Function

Format

Parameters

Views

Default Level

Task Name and Operations

Usage Guidelines

Example