V-217096

Discussion

To avoid global visibility of local information, there are a number of source-group (S, G) states in a PIM-SM domain that must not be leaked to another domain, such as multicast sources with private address, administratively scoped multicast addresses, and the auto-RP groups (224.0.1.39 and 224.0.1.40). Allowing a multicast distribution tree, local to the core, to extend beyond its boundary could enable local multicast traffic to leak into other autonomous systems and customer networks.

Check Content

Review the router configuration to determine if there is export policy to block local source-active multicast advertisements.

Verify that the router is configured with an export policy to filter multicast source-active advertisements.

policy-options {
   …
    …
    …
    }
    policy-statement SA_EXPORT {
        term INTERNAL_GROUP {
            from {
                route-filter 239.0.0.0/8 orlonger;
            }
            then reject;
        }
        term INTERNAL_ADDR {
            from {
                source-address-filter 10.0.0.0/8 orlonger;
            }
            then reject;
        }
        term ACCEPT_OTHERS {
            then accept;
        }
    }

Verify that an export source-active filter has been applied to MSDP.

protocols {
    …
    …
    …
    }
    msdp {
       export SA_EXPORT;

If the router is not configured with an export policy to block local source-active multicast advertisements, this is a finding.