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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-216646	CISC-RT-000060	SV-216646r531086_rule		Low

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.

STIG	Date
Cisco IOS XE Router RTR Security Technical Implementation Guide	2021-03-26

Details

Check Text ( C-17879r287898_chk )
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 Text (F-17877r287899_fix)
Disable all inactive interfaces as shown below: R4(config)#interface GigabitEthernet3 R4(config-if)#shutdown R4(config)#interface GigabitEthernet4 R4(config-if)#shutdown