peer soo (BGP-VPN instance IPv4 address family view)

Function

The peer soo command configures the Site of Origin (SoO) attribute for an EBGP peer in a BGP VPN instance.

The undo peer soo command cancels the configuration.

By default, no SoO attribute is configured for an EBGP peer in a BGP VPN instance.

Format

peer ipv4-address soo site-of-origin

undo peer ipv4-address soo

Parameters

Parameter	Description	Value
ipv4-address	Specifies the IPv4 address of a BGP peer.	It is in dotted decimal notation.
site-of-origin	Specifies the SoO attribute.	The SoO attribute is a BGP extended community attribute and can be expressed in any of the following formats: 2-byte AS number:4-byte user-defined number, for example, 1:3 The AS number ranges from 0 to 65535, and the user-defined number ranges from 0 to 4294967295. The AS number and user-defined number cannot both be set to 0. This means that the value of the SoO attribute cannot be 0:0. IPv4-address:2-byte user-defined number, for example, 192.168.122.15:1 The IP address ranges from 0.0.0.0 to 255.255.255.255, and the user-defined number ranges from 0 to 65535. Integral 4-byte AS number:2-byte user-defined number, for example, 0:3 or 65537:3. An AS number ranges from 65536 to 4294967295. A user-defined number ranges from 0 to 65535. The AS number and user-defined number cannot be both 0s. That is, the value of the SoO attribute cannot be 0:0. 4-byte AS number in dotted notation:2-byte user-defined number, for example, 0.0:3 or 0.1:0. A 4-byte AS number in dotted notation is in the format of x.y, where x and y are integers that range from 1 to 65535 and from 0 to 65535, respectively. A user-defined number ranges from 0 to 65535. The AS number and user-defined number cannot be both 0s. That is, the value of the SoO attribute cannot be 0.0:0.

Parameter

Description

Value

ipv4-address

Specifies the IPv4 address of a BGP peer.

It is in dotted decimal notation.

site-of-origin

Specifies the SoO attribute.

The SoO attribute is a BGP extended community attribute and can be expressed in any of the following formats:

2-byte AS number:4-byte user-defined number, for example, 1:3 The AS number ranges from 0 to 65535, and the user-defined number ranges from 0 to 4294967295. The AS number and user-defined number cannot both be set to 0. This means that the value of the SoO attribute cannot be 0:0.
IPv4-address:2-byte user-defined number, for example, 192.168.122.15:1 The IP address ranges from 0.0.0.0 to 255.255.255.255, and the user-defined number ranges from 0 to 65535.
Integral 4-byte AS number:2-byte user-defined number, for example, 0:3 or 65537:3. An AS number ranges from 65536 to 4294967295. A user-defined number ranges from 0 to 65535. The AS number and user-defined number cannot be both 0s. That is, the value of the SoO attribute cannot be 0:0.
4-byte AS number in dotted notation:2-byte user-defined number, for example, 0.0:3 or 0.1:0. A 4-byte AS number in dotted notation is in the format of x.y, where x and y are integers that range from 1 to 65535 and from 0 to 65535, respectively. A user-defined number ranges from 0 to 65535. The AS number and user-defined number cannot be both 0s. That is, the value of the SoO attribute cannot be 0.0:0.

Views

BGP-labeled VPN instance IPv4 address family view, BGP-VPN instance IPv4 address family view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
bgp	write

Usage Guidelines

Usage Scenario

In a L3VPN scenario, if the ASs to which two VPN sites belong use private AS numbers, the AS numbers of the two VPN sites may be the same. As a result, different sites of the same VPN cannot communicate. The peer substitute-as command can be used to enable AS number substitution on PEs to address this problem.

Enabling AS number substitution will cause another problem. Several CEs at a VPN site may establish EBGP connections with different PEs of a L3VPN backbone network, and a routing protocol has been configured on the CEs. If AS number substitution is enabled on PEs, the AS numbers carried by VPN routes of this site will be replaced on the PEs. As a result, routes advertised from a CE to a PE may be re-advertised to this VPN site after the routes traverse the backbone network, causing a routing loop. The peer soo command can be run on the PEs to address this problem.

After the peer soo command is run on a PE to configure the SoO attribute for a specified CE, the PE adds the attribute to a route sent from the CE and advertises the route to the remote PE. The remote PE checks the SoO attribute of the route before sending it to its attached CE. If the SoO attribute is the same as the local SoO attribute on the remote PE, the remote PE does not send the route to its attached CE, preventing a routing loop in a VPN site.

Precautions

The peer soo command is used only in the scenarios where PEs and CEs establish EBGP peer relationships.

Example

# Configure the SoO attribute.

<HUAWEI> system-view
[~HUAWEI] ip vpn-instance vpna
[*HUAWEI-vpn-instance-vpna] ipv4-family
[*HUAWEI-vpn-instance-vpna-af-ipv4] route-distinguisher 100:1
[*HUAWEI-vpn-instance-vpna-af-ipv4] quit
[*HUAWEI-vpn-instance-vpna] quit
[*HUAWEI] bgp 100
[*HUAWEI-bgp] ipv4-family vpn-instance vpna
[*HUAWEI-bgp-vpna] peer 1.1.1.1 as-number 100
[*HUAWEI-bgp-vpna] peer 1.1.1.1 soo 2.2.2.2:45