V-283832

Discussion

Using a loopback address as the source address offers a multitude of uses for security, access, management, and scalability of backbone routers. It is easier to construct appropriate ingress filters for router management plane traffic destined to the network management subnet since the source addresses will be from the range used for loopback interfaces instead of from a larger range of addresses used for physical interfaces. Log information recorded by authentication and syslog servers will record the router's loopback address instead of the numerous physical interface addresses.

Check Content

Review the router configuration to determine if it uses its loopback address as the source address for LDP peering sessions.

Verify a loopback address has been configured, as shown in the following example:

- show router ldp discovery detail | match "Local Address"
Local Address      : 3.3.3.3:0

If the router is not configured to use its loopback address for LDP peering, this is a finding.