You can create an as-path access-list to only allow certain ASes into your network.
If the AS number was 100, you could do something like:
ip as-path access-list 1 permit _100_
ip as-path access-list 1 permit _100$
route-map DenyAS deny 10
match as-path 1
route-map DenyAS permit 20
router bgp 400
neighbor route-map DenyAS in
The as-path acl will match on anything coming from 100 or through 100 and deny based on the route map. (The second line doesn't necessarily need to exist in the as-path acl, but I put it in there for good measure.)
HTH,
John
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HTH,
John
*** Please rate all useful posts ***