IP AS-Path Access List

IP AS-path access lists define ordered permit/deny rules that match the AS_PATH attribute of BGP routes using regular expressions. Each entry carries a sequence number, an action, and a regular expression, and the list is evaluated in sequence order. AS-path access lists are referenced from route map match clauses (match as-path and match as-number as-path-list) to implement AS-path based routing policies such as filtering routes originated by or transiting a specific autonomous system.

Diagram

Classes

nxos

Name	Type	Constraint	Mandatory	Default Value
devices	List	devices	No
device_groups	List	device_groups	No
global	Class	global	No
templates	List	templates	No

devices (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

device_groups (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

global (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

templates (nxos)

Name	Type	Constraint	Mandatory	Default Value
configuration	Class	configuration	No

configuration (nxos.devices)

Name	Type	Constraint	Mandatory	Default Value
ip_as_path_access_lists	List	ip_as_path_access_lists	No

ip_as_path_access_lists (nxos.devices.configuration)

Name	Type	Constraint	Mandatory	Default Value
name	String		Yes
entries	List	entries	No

entries (nxos.devices.configuration.ip_as_path_access_lists)

Name	Type	Constraint	Mandatory	Default Value
seq	Integer	min: 1, max: 4294967294	Yes
action	Choice	permit, deny	No
regex	String		No

Examples

Example 1: AS-path access list denying routes that traverse a specific AS

nxos:
  devices:
    - name: BORDER-LEAF1
      configuration:
        ip_as_path_access_lists:
          - name: ASPATH-DENY-65110
            entries:
              - seq: 10
                action: deny
                regex: "_65110_"
              - seq: 20
                action: permit
                regex: ".*"

Example 2: AS-path access lists referenced from a route map

nxos:
  devices:
    - name: BORDER-LEAF1
      configuration:
        ip_as_path_access_lists:
          - name: ASPATH-LOCAL
            entries:
              - seq: 10
                action: permit
                regex: "^$"
          - name: ASPATH-PEER-65200
            entries:
              - seq: 10
                action: permit
                regex: "^65200_"
        route_maps:
          - name: RM-EXPORT
            entries:
              - order: 10
                action: permit
                match_as_path:
                  - ASPATH-LOCAL
                  - ASPATH-PEER-65200