Configuring an AS_Path Filter

Context

An AS_Path filter is used to filter routes based on the AS_Path attributes of BGP routes. If you do not want to receive routes of a specified AS number, configure an AS_Path filter based on the specified AS number. On a complex network, multiple ACLs or IP prefix lists must be configured to filter BGP routes. This can be a complicated process; configuring an AS_Path filter can simplify the configuration.

Procedure

Run system-view
The system view is displayed.
Run ip as-path-filter { as-path-filter-number | as-path-filter-name } { permit | deny } regular-expression
An AS_Path filter is configured.

In the preceding command, regular-expression indicates that the AS_Path filter uses a regular expression to define matching rules.

Verifying the Configuration

Run the display ip as-path-filter [ as-path-filter-number | as-path-filter-name ] command to check information about a configured AS_Path filter.