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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-60893	AMLS-L3-000130	SV-75351r1_rule		Medium

Description
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.

Description

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.

STIG	Date
Arista MLS DCS-7000 Series RTR Security Technical Implementation Guide	2016-03-29

Details

Check Text ( C-61841r1_chk )
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.

Check Text ( C-61841r1_chk )

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 (F-66605r1_fix)
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]

Fix Text (F-66605r1_fix)

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]