NET-VLAN-006 - The VLAN1 is being used for management traffic.

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This audit has been deprecated and will be removed in a future update.

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Information

The IAO/NSO will ensure VLAN1 is not used for in-band management traffic. A dedicated management VLAN or VLANs will be defined to keep management traffic separate from user data and control plane traffic.

All ports, including the internal sc0 interface, are configured by default to be members of VLAN 1. In a VLAN-based network, switches use VLAN1 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.

NOTE: This check is derived from the L3 switch guidance, if the scan target is a router the check can be ignored.
NOTE: This check requires manual verification. If switch clustering is used, review the configuration of the VLAN command switch and look for the command cluster management-vlan. The new management VLAN ID follows this command.
NOTE: Nessus has not performed this check. Please review the benchmark to ensure target compliance.

For unclustered switches, review the configuration of each switch. All ports, including the internal management interface (sc0), are configured by default to be members of VLAN 1. The management VLAN can be identified by its switch virtual interface (SVI) defined that contains the IP address for the internal management interface.

Solution

Best practices for VLAN-based networks is create a dedicated management VLAN, prune unnecessary ports from gaining access to VLAN1 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_Infrastructure_Router_L3_Switch_V8R29_STIG.zip

Item Details

References: CAT|II, Rule-ID|SV-5628r2_rule, STIG-ID|NET-VLAN-006, Vuln-ID|V-5628

Plugin: Cisco

Control ID: 1401dd16262f012da1d568b6671774745275405e8a09e034431989d6808af22f