apply-label per-nexthop (BGP-VPNv6 address family view)

Function

The apply-label per-nexthop command enables one-label-per-next-hop label distribution on an ASBR.

The undo apply-label per-nexthop command disables one-label-per-next-hop label distribution on an ASBR.

One-label-per-next-hop label distribution is disabled. An ASBR assigns a unique label to each route.

By default, one-label-per-next-hop label distribution is disabled. An ASBR assigns a unique label to each route.

Format

apply-label per-nexthop

undo apply-label per-nexthop

Parameters

None

Views

BGP-VPNv6 address family view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
bgp	write

Usage Guidelines

Usage Scenario

In an HVPN or inter-AS VPN Option B scenario, if an SPE or ASBR does not have sufficient MPLS label resources for VPN routes, run the apply-label per-nexthop command to minimize MPLS label consumption on the SPE or ASBR.

By default, an SPE or ASBR assigns a unique label to each VPN route to be advertised to its MP-BGP peers. After the apply-label per-nexthop command is run, the SPE or ASBR assigns only one label to routes that share the same next hop and outgoing label. To ensure that the routes learned by an SPE or ASBR from the same next hop have the same outgoing label, run the apply-label per-instance command on each PE. Otherwise, the apply-label per-nexthop command does not take effect.

Configuration Impact

After one-label-per-next-hop label distribution is enabled or disabled, the labels assigned by the SPE or ASBR to routes change. As a result, temporary packet loss may occur.

Example

# Configure an ASBR to assign only one label to VPNv6 routes that share the same next hop and outgoing label.

<HUAWEI> system-view
[~HUAWEI] bgp 100
[*HUAWEI-bgp] ipv6-family vpnv6
[*HUAWEI-bgp-af-vpnv6] apply-label per-nexthop