ASN Filtering

Cisco Examples Here

Example Junos bogon ASN filtering:

    policy-options {
        as-path-group bogon-asns {
            /* rfc7607 */
            as-path zero ".* 0 .*";
            /* RFC 4893 AS_TRANS */
            as-path as_trans ".* 23456 .*";
            /* RFC 5398 and documentation/example ASNs */
            as-path examples1 ".* [64496-64511] .*";
            as-path examples2 ".* [65536-65551] .*";
            /* RFC 6996 Private ASNs*/
            as-path reserved1 ".* [64512-65534] .*";
            as-path reserved2 ".* [4200000000-4294967295] .*";
            /* RFC 6996 Last 32 and 64 bit ASNs */
            as-path last32 ".* 65535 .*";
            as-path last64 ".* 4294967295 .*";
            /* RFC IANA reserved ASNs*/
            as-path iana-reserved ".* [65552-131071] .*";
        }
        policy-statement import_from_ebgp {
            term bogon-asns {
                from as-path-group bogon-asns;
                then reject;
            }
            term .....
        }
    }

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