ext-community-change enable (BGP-IPv4 unicast address family view)

Function

The ext-community-change enable command allows a routing policy to modify the VPN target extended community attribute, SoO extended community attribute, and link-bandwith attribute.

The undo ext-community-change enable command disables the VPN target extended community attribute, SoO extended community attribute, and link-bandwith attribute from being modified using a routing policy.

By default, a BGP device cannot use route-policies to change the VPN target extended community attribute, SoO extended community attribute, and link-bandwith attribute in matched BGP routes.

Format

ext-community-change enable

undo ext-community-change enable

Parameters

None

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

By default, BGP prevents a device from using a route-policy to change the VPN target extended community attribute, SoO extended community attribute, and link-bandwith attribute in the matched routes either learned from or to be advertised to a peer or peer group. To enable a device to use route-policies to change the VPN target extended community attribute, SoO extended community attribute, and link-bandwith attribute in matched routes, run the ext-community-change enable command. After running this command, you can configure an import route-policy to change the VPN target extended community attribute, SoO extended community attribute, and link-bandwith attribute in the matched routes received from a peer or peer group. You can also configure an export route-policy to filter the optimal routes selected by BGP and then change the VPN target extended community attribute, SoO extended community attribute, and link-bandwith attribute in the matched routes that are to be advertised to the peer or peer group.

Prerequisites

The BGP view or a specified address family view has been displayed.

Precautions

The ext-community-change enable and peer route-policy import commands must both be run so that the device can use an import policy to change extended community attributes of the routes learned from a peer or peer group.
The ext-community-change enable command must be run with either of the following commands so that the extended community attributes changed based on an export policy can be advertised to a peer or peer group:
a.peer advertise-ext-community
b.peer route-policy export
The ext-community-change enable command allows a device to use only route-policies to change the VPN-Target and SoO extended community attributes in matched routes.

Example

# Enable the device to change extended community attributes based on a route-policy.

<HUAWEI> system-view
[~HUAWEI] bgp 100
[*HUAWEI-bgp] ext-community-change enable