bestroute nexthop-resolved (BGP-IPv4 unicast address family view)

Function

The bestroute nexthop-resolved ip command configures the labeled routes that recurse to IP addresses to participate in route selection.

The bestroute nexthop-resolved tunnel command configures the labeled routes that recurse to LSPs to participate in route selection.

The undo bestroute nexthop-resolved command restores the default configuration.

By default, the BGP IPv4 unicast routes that recurse to IP addresses routes participate in route selection.

Format

bestroute nexthop-resolved { ip | tunnel [ inherit-ip-cost ] }

undo bestroute nexthop-resolved

undo bestroute nexthop-resolved tunnel inherit-ip-cost

Parameters

Parameter	Description	Value
ip	Allows labeled routes that recurse to IP addresses to participate in route selection.	-
tunnel	Allows labeled routes that recurse to LSPs to participate in route selection.	-
inherit-ip-cost	Allows the labeled routes that recurse to IP addresses to inherit the cost values of corresponding IP routes during route selection.	-

Parameter

Description

Value

Allows labeled routes that recurse to IP addresses to participate in route selection.

tunnel

Allows labeled routes that recurse to LSPs to participate in route selection.

inherit-ip-cost

Allows the labeled routes that recurse to IP addresses to inherit the cost values of corresponding IP routes during route selection.

Views

BGP-IPv4 unicast address family view, BGP view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
bgp	write

Usage Guidelines

Usage Scenario

In non-RR networking, or RR networking where the BGP next hop is changed, BGP needs to check whether there is an LSP destined for the next hop. If such an LSP is unavailable, BGP needs to establish one. If the default setting is adopted, a labeled BGP IPv4 unicast route may be selected prior to LSP establishment. As a result, services are incorrectly switched before LSP establishment, packet loss may occur, which affects service stability. The bestroute nexthop-resolved tunnel command can be run to allow route selection only after the labeled BGP IPv4 route recurses to an LSP.

In RR networking, if a router only transmits routing information and other routes forwards traffic, you can configure labeled BGP IPv6 unicast routes that recurse to IP addresses to participate in route selection. The bestroute nexthop-resolved command is not applied to the unlabeled routes in the IPv6 unicast address family.

Configuration Impact

The bestroute nexthop-resolved ip command is mutually exclusive with the bestroute nexthop-resolved tunnel command.

The bestroute nexthop-resolved tunnel command is mutually exclusive with the bestroute nexthop-resolved tunnel inherit-ip-cost command.

Example

# In the BGP IPv4 unicast view, configure labeled BGP IPv4 unicast routes that recurse to LSPs to participate in route selection.

<HUAWEI> system-view
[~HUAWEI] bgp 100
[*HUAWEI-bgp] ipv4-family unicast
[*HUAWEI-bgp-af-ipv4] bestroute nexthop-resolved tunnel