peer soo

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 deletes the SoO.

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

Format

peer { group-name | ipv4-address | ipv6-address } soo site-of-origin

undo peer { group-name | ipv4-address | ipv6-address } soo

Parameters

Parameter	Description	Value
group-name	Specifies the name of a BGP peer group.	The name is a string of 1 to 47 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string.
ipv4-address	Specifies the IPv4 address of a BGP peer.	It is in dotted decimal notation.
ipv6-address	Specifies the IPv6 address of a BGP peer.	The address is in the format of X:X:X:X:X:X:X:X.
Site-of-origin	Specifies the SoO attribute, which 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. The user-defined number ranges from 0 to 4294967295. The AS number and the user-defined number cannot both be 0. That is, a SoO 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. The user-defined number ranges from 0 to 65535. Integral 4-byte AS number:2-byte user-defined number, for example, 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, a SoO 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 0 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, a SoO cannot be 0.0:0.	-

Views

BGP-VPN instance IPv4 address family view or BGP-VPN instance IPv6 address family view

Default Level

2: Configuration level

Usage Guidelines

Usage Scenario

In a BGP/MPLS IP VPN 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 BGP/MPLS IP VPN 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 for EBGP peers in a BGP VPN instance.

<HUAWEI> system-view
[HUAWEI] bgp 100
[HUAWEI-bgp] ipv4-family vpn-instance vpna
[HUAWEI-bgp-vpna] peer 192.168.15.2 soo 10.2.2.2:45