The Cisco switch must not use the default VLAN for management traffic.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-220693	CISC-L2-000240	SV-220693r991949_rule		Medium

Description
Switches use the default VLAN (i.e., VLAN 1) for in-band management and to communicate with directly connected switches using Spanning-Tree Protocol (STP), Dynamic Trunking Protocol (DTP), VLAN Trunking Protocol (VTP), and Port Aggregation Protocol (PAgP)—all untagged traffic. As a consequence, the default VLAN may unwisely span the entire network if not appropriately pruned. If its scope is large enough, the risk of compromise can increase significantly.

Description

Switches use the default VLAN (i.e., VLAN 1) for in-band management and to communicate with directly connected switches using Spanning-Tree Protocol (STP), Dynamic Trunking Protocol (DTP), VLAN Trunking Protocol (VTP), and Port Aggregation Protocol (PAgP)—all untagged traffic. As a consequence, the default VLAN may unwisely span the entire network if not appropriately pruned. If its scope is large enough, the risk of compromise can increase significantly.

STIG	Date
Cisco NX OS Switch L2S Security Technical Implementation Guide	2024-06-06

Details

Check Text ( C-22408r539130_chk )
Review the switch configuration and verify that the default VLAN is not used to access the switch for management. interface Vlan1 interface Vlan44 description Management VLAN ip address 10.1.12.1/24 If the default VLAN is being used for management access to the switch, this is a finding.

Fix Text (F-22397r539131_fix)
Configure the switch for management access to use a VLAN other than the default VLAN. SW1(config)# interface vlan 44 SW1(config-if)# ip add 10.1.12.1/24 SW1(config-if)# end