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-216646	SRG-NET-000019-RTR-000007	CISC-RT-000060	SV-216646r531086_rule	2024-11-25	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 GigabitEthernet3 shutdown ! interface GigabitEthernet4 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