Details

Protocol Independent Multicast (PIM) is a routing protocol used to build multicast distribution trees for forwarding multicast traffic across the network infrastructure. Protocol Independent Multicast traffic must be limited to only known PIM neighbors by configuring and binding a PIM neighbor filter to those interfaces that have PIM enabled. If a PIM neighbor filter is not applied to those interfaces that have PIM enabled, unauthorized routers can join the PIM domain and discover and use the rendezvous points and also advertise their rendezvous points into the domain. This can result in a denial of service by traffic flooding or result in the unauthorized transfer of data.

NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.

Solution

Configure neighbor filters to only accept PIM control plane traffic from documented PIM neighbors. Bind neighbor filters to all PIM-enabled interfaces.

To create a new neighbor filter, create an access list by entering:

ip access-list [name]
[ip access list permit/deny statement]
exit

Then apply the neighbor filter based on the accesslist to the PIM-enabled interface:

int ethernet 1
ip pim neighbor-filter [name-of-ACL]

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Arista_MLS_DCS-7000_Series_Y20M07_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: Access Control.This control applies to the following type of system Arista.

References

• 800-53|AC-4
• CAT|II
• CCI|CCI-001414
• Group-ID|V-60891
• Rule-ID|SV-75349r1_rule
• STIG-ID|AMLS-L3-000120
• Vuln-ID|V-60891

Source

• Tenable.com/audits