The Arista Multilayer Switch must establish boundaries for IPv6 Admin-Local, IPv6 Site-Local, IPv6 Organization-Local scope, and IPv4 Local-Scope multicast traffic.

From Arista MLS DCS-7000 Series RTR Security Technical Implementation Guide

Part of SRG-NET-000019-RTR-000005

Associated with: CCI-001414

SV-75351r1_rule The Arista Multilayer Switch must establish boundaries for IPv6 Admin-Local, IPv6 Site-Local, IPv6 Organization-Local scope, and IPv4 Local-Scope multicast traffic.

Vulnerability discussion

If multicast traffic is forwarded beyond the intended boundary, it is possible that it can be intercepted by unauthorized or unintended personnel.Administrative scoped multicast addresses are locally assigned and are to be used exclusively by the enterprise network or enclave. Administrative scoped multicast traffic must not cross the enclave perimeter in either direction. Restricting multicast traffic makes it more difficult for a malicious user to access sensitive traffic.Admin-Local scope is encouraged for any multicast traffic within a network intended for network management, as well as for control plane traffic that must reach beyond link-local destinations.

Check content

Review the multicast topology diagram to determine if there are any documented Admin-Local (FFx4::/16), Site-Local (FFx5::/16), or Organization-Local (FFx8::/16) multicast boundaries for IPv6 traffic or any Local-Scope (239.255.0.0/16) boundaries for IPv4 traffic. Verify the appropriate boundaries are configured on the applicable multicast-enabled interfaces via an "ip multicast boundary" statement in the interface configuration. If the appropriate boundaries are not configured on applicable multicast-enabled interfaces, this is a finding.

Fix text

Configure the appropriate boundaries to contain packets addressed within the administratively scoped zone. Defined multicast addresses are FFx4::/16, FFx5::/16, FFx8::/16, and 239.255.0.0/16. To create a PIM Boundary, create an access list by entering: ip access-list [name] [ip access list permit/deny statement] exit Then apply the boundary filter based on the accesslist to the PIM-enabled interface: int ethernet [X] ip multicast boundary [name-of-ACL]

Pro Tips

Lavender hyperlinks in small type off to the right (of CSS class id, if you view the page source) point to globally unique URIs for each document and item. Copy the link location and paste anywhere you need to talk unambiguously about these things.

You can obtain data about documents and items in other formats. Simply provide an HTTP header Accept: text/turtle or Accept: application/rdf+xml.

Powered by sagemincer