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. NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.
Configure the switch for management access to use a VLAN other than the default VLAN: SW1(config)#int vlan 22 SW1(config-if)#ip add 10.1.22.3 255.255.255.0 SW1(config-if)#no shut