The layer 2 switch must not use the default VLAN for management traffic.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-206669	SRG-NET-000512-L2S-000010	SV-206669r385561_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.

STIG	Date
Layer 2 Switch Security Requirements Guide	2025-03-05

Details

Check Text (C-6927r298437_chk)

Review the switch configuration and verify that the default VLAN is not used to access the switch for management.

If the default VLAN is being used to access the switch, this is a finding.

Fix Text (F-6927r298438_fix)

Configure the switch for management access to use a VLAN other than the default VLAN.