V-216646

Discussion

An inactive interface is rarely monitored or controlled and may expose a network to an undetected attack on that interface. Unauthorized personnel with access to the communication facility could gain access to a router by connecting to a configured interface that is not in use. If an interface is no longer used, the configuration must be deleted and the interface disabled. For sub-interfaces, delete sub-interfaces that are on inactive interfaces and delete sub-interfaces that are themselves inactive. If the sub-interface is no longer necessary for authorized communications, it must be deleted.

Check Content

Review the router configuration and verify that inactive interfaces have been disabled as shown below:

interface GigabitEthernet3
 shutdown
!
interface GigabitEthernet4
 shutdown
 
If an interface is not being used but is configured or enabled, this is a finding.