Disable the BGP4+ AS_PATH Check Function

When you disable the AS_PATH check function for routes learned from a specific location, BGP does not reject routes that contain the recipient BGP speaker's AS number.

Procedure

  1. Access global configuration mode.
    device# configure terminal
  2. Access BGP configuration mode.
    device(config)# router bgp
  3. Access IPv6 address family unicast configuration mode.
    device(config-bgp-router)# address-family ipv6 unicast
  4. Disable the BGP AS_PATH check function.
    device(config-bgp-ipv6u)# neighbor 2001:db8:e0ff:783a::4 allowas-in 3
    This example specifies the neighbor allowas-in command, the IPv6 address of the neighbor, and the variable 3, which represents the number of times that the AS path of a received route can contain the BGP speaker's ASN and still be accepted.

Example

The following example summarizes the commands in this procedure.

device# configure terminal
device(config)# router bgp
device(config-bgp-router)# address-family ipv6 unicast
device(config-bgp-ipv6u)# neighbor 2001:db8:e0ff:783a::4 allowas-in 3