Title

The RUCKUS ICX BGP router must be configured to reject route advertisements from CE routers with an originating AS in the AS_PATH attribute that does not belong to that customer. (Cat III impact)

Discussion

Verifying the path a route has traversed will ensure the local AS is not used as a transit network for unauthorized traffic. To ensure that the local AS does not carry any prefixes that do not belong to any customers, all PE routers must be configured to reject routes with an originating AS other than that belonging to the customer.

Check Content

This requirement is not applicable for the DODIN Backbone. Review ICX router configuration for AS_PATH filter statements for BGP: ip as-path access-list BGP_filter seq 5 permit ^yy$ ip as-path access-list BGP_filter seq 10 deny .* ! router bgp local-as xx neighbor x.4.4.4 remote-as yy neighbor x.4.4.4 filter-list BGP_filter in ! If the ICX router is not configured to reject updates from CE routers with an originating AS in the AS_PATH attribute that does not belong to that customer, this is a finding.

Fix Text

Configure the router to reject updates from CE routers with an originating AS in the AS_PATH attribute that does not belong to that customer. 1. Configure the AS_PATH filter list. ICX(config)# ip as-path access-list BGP_filter seq 5 permit ^yy$ ICX(config)# ip as-path access-list BGP_filter seq 10 deny .* 2. Apply to BGP neighbor. ICX(config)# router bgp ICX(config-bgp-router)# neighbor x.x.x.x filter-list BGP_filter in

Additional Identifiers

Rule ID: SV-273578r1110887_rule

Vulnerability ID: V-273578

Group Title: SRG-NET-000018-RTR-000010

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.