The PE router providing MPLS Layer 2 Virtual Private Network (L2VPN) services must be configured to authenticate targeted Label Distribution Protocol (LDP) sessions used to exchange virtual circuit (VC) information using a FIPS-approved message authentication code algorithm.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-256028	ARST-RT-000480	SV-256028r882426_rule		Medium

Description
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.

Description

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.

STIG	Date
Arista MLS EOS 4.2x Router Security Technical Implementation Guide	2023-01-17

Details

Check Text ( C-59704r882424_chk )
Review the Arista router configuration to determine if LDP messages are being authenticated for the targeted LDP sessions. Step 1: Verify the Arista router configuration to verify LDP is configured globally and router-id is set. mpls ldp router-id [x.x.x.x \| interface] LoopbackY no shutdown Step 2: Verify the Arista router configuration to ensure the password is configured for LDP neighbor. mpls ldp password [type] [password] Step 3: Enable the mpls globally or per interface. For Global: mpls ip For interfaces: interface Ethernet 1 mpls ip If authentication is not being used for the LDP sessions using a FIPS-approved message authentication code algorithm, this is a finding.

Check Text ( C-59704r882424_chk )

Review the Arista router configuration to determine if LDP messages are being authenticated for the targeted LDP sessions.

Step 1: Verify the Arista router configuration to verify LDP is configured globally and router-id is set.

mpls ldp
router-id [x.x.x.x | interface] LoopbackY
no shutdown

Step 2: Verify the Arista router configuration to ensure the password is configured for LDP neighbor.

mpls ldp
password [type] [password]

Step 3: Enable the mpls globally or per interface.

For Global:

mpls ip

For interfaces:

interface Ethernet 1
mpls ip

If authentication is not being used for the LDP sessions using a FIPS-approved message authentication code algorithm, this is a finding.

Fix Text (F-59647r882425_fix)
Implement authentication for all targeted LDP sessions using a FIPS-approved message authentication code algorithm. Step 1: Configure the mpls LDP on the Arista MLS. PE11(config)#mpls ldp PE11(config-mpls-ldp)#router-id interface Loopback0 PE11(config-mpls-ldp)#no shutdown Step 2: Enable the authentication for LDP neighbors. PE11(config-mpls-ldp)#password 0 xxxxx