Usage Scenario
SoO records the BGP route originator. To configure an SoO extended community filter so that BGP routes carrying SoO can be filtered, run the ip extcommunity-list soo command.
An SoO extended community filter can be used as a matching condition of a route-policy using a command, such as the
if-match extcommunity-list soo aaa command.
The relationship between the rules of the SoO extended community filter is "AND".
The
undo ip extcommunity-list soo command deletes a specified SoO extended community filter.
The
display ip extcommunity-list soo command displays detailed configurations of the SoO extended community filter.
Precautions
The extended community attributes of a route include VPN-target and SoO. The ip extcommunity-list soo command adds an SoO extended community filter.
By default, Source of Origin (SoO) extended community filters work in deny mode. If all matching rules in a filter are configured to work in deny mode, all routes are denied by the filter; to prevent this problem, configure one matching rule in permit mode after one or multiple matching rules in deny mode so that the routes except for those denied by preceding matching rules are permitted by the filter.
For an advanced SoO extended community filter, if the SoO attribute is set to be in the format of 4-byte AS number:2-byte user-defined number, the filtering rule that uses the SoO-based regular expression is affected by the
as-notation plain command:
- If the as-notation plain command is run, route matching can succeed only after the regular expression is set to be in the format of integral 4-byte AS number:2-byte user-defined number.
- If the as-notation plain command is not run, route matching can succeed only after the regular expression is set to be in the format of 4-byte AS number in dotted notation:2-byte user-defined number.
Note: If the as-notation plain command is run after the regular expression is configured, you need to reconfigure the RD value using the rdStr parameter; otherwise, route matching may fail against an import or export route-policy, causing a network fault.