NET-VLAN-004 - VLAN 1 is being used as a user VLAN - 'shutdown'.

Information

VLAN 1 must not be used for user VLANs.

In a VLAN-based network, switches use VLAN 1 as the default VLAN for in-band management and to communicate with other networking devices using Spanning-Tree Protocol (STP), Cisco Discovery Protocol (CDP), Dynamic Trunking Protocol (DTP), VLAN Trunking Protocol (VTP), and Port Aggregation Protocol (PAgP)--all untagged traffic. As a consequence, VLAN 1 may unwisely span the entire network if not appropriately pruned. If its scope is large enough, the risk of compromise can increase significantly.

Solution

Best practices for VLAN-based networks is to prune unnecessary ports from gaining access to VLAN 1 as well as the management VLAN, and to separate in-band management, device protocol, and data traffic.

See Also

https://iasecontent.disa.mil/stigs/zip/U_Network_L2_Switch_V8R27_STIG.zip

Item Details

Category: ACCESS CONTROL

References: 800-53|AC-4(21), CAT|II, Rule-ID|SV-3971r2_rule, STIG-ID|NET-VLAN-004, Vuln-ID|V-3971

Plugin: Cisco

Control ID: 7bd37112527ad808c3268b6d61c472838de05d6325d6c8d8ea6ccbf96c2cfbb8