Title

The router providing MPLS L2VPN services must be configured to authenticate targeted LDP sessions used to exchange VC information using a FIPS-approved message authentication code algorithm. (Cat II impact)

Discussion

Label Distribution Protocol (LDP) provides the signaling required for setting up and tearing down pseudowires (virtual circuits used to transport layer 2 frames) across an MPLS IP core network. Using a targeted LDP session, each PE router advertises a virtual circuit label mapping that is used as part of the label stack imposed on the frames by the ingress PE router during packet forwarding. Authentication provides protection against spoofed TCP segments that can be introduced into the LDP sessions.

Check Content

Review the router configuration to determine if LDP messages are being authenticated for the targeted LDP sessions. [edit protocols] ldp { interface <interface 1 name>.<logical unit>; interface <interface 2 name>.<logical unit>; session <Session destination address> { authentication-algorithm <aes-128-cmac-96|hmac-sha-1-96>; authentication-key-chain <name>; } } If authentication is not being used for the LDP sessions using a FIPS-approved message authentication code algorithm, this is a finding.

Fix Text

Implement authentication for all targeted LDP sessions using a FIPS-approved message authentication code algorithm. set protocols ldp interface <interface 1 name>.<logical unit> set protocols ldp interface <interface 2 name>.<logical unit> set protocols ldp session <Session destination address> authentication-algorithm <aes-128-cmac-96|hmac-sha-1-96> set protocols ldp session <Session destination address> authentication-key-chain <name>

Additional Identifiers

Rule ID: SV-254028r844260_rule

Vulnerability ID: V-254028

Group Title: SRG-NET-000343-RTR-000001

Expert Comments

CCIs tied to check.

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