The Cisco router must be configured to have all inactive interfaces disabled.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
low	V-216740	SRG-NET-000019-RTR-000007	CISC-RT-000060	SV-216740r531087_rule	2024-08-22	3

Description
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.

Description

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.

ℹ️ Check
Review the router configuration and verify that inactive interfaces have been disabled as shown below. interface GigabitEthernet0/0/1/0 shutdown ! interface GigabitEthernet0/0/1/1 shutdown If an interface is not being used but is configured or enabled, this is a finding.

✔️ Fix
Disable all inactive interfaces as shown below. R4(config)#interface GigabitEthernet3 R4(config-if)#shutdown R4(config)#interface GigabitEthernet4 R4(config-if)#shutdown