Check: CISC-L2-000220
Cisco IOS XE Switch L2S STIG:
CISC-L2-000220
(in versions v2 r5 through v1 r0.1)
Title
The Cisco switch must not have the default VLAN assigned to any host-facing switch ports. (Cat II impact)
Discussion
In a VLAN-based network, switches use the default VLAN (i.e., VLAN 1) for in-band management and to communicate with other networking devices 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.
Check Content
Review the switch configurations and verify that no access switch ports have been assigned membership to the default VLAN (i.e., VLAN 1). VLAN assignments can be verified via the show vlan command. SW1#show vlan VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active 10 User VLAN active Gi0/3, Gi1/0, Gi1/1, Gi1/2 Gi1/3, Gi2/1 20 Management VLAN active Gi0/2 999 VLAN0999 active Gi2/0 If there are access switch ports assigned to the default VLAN, this is a finding.
Fix Text
Remove the assignment of the default VLAN from all access switch ports.
Additional Identifiers
Rule ID: SV-220668r539671_rule
Vulnerability ID: V-220668
Group Title: SRG-NET-000512-L2S-000008
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-000366 |
The organization implements the security configuration settings. |
Controls
Number | Title |
---|---|
CM-6 |
Configuration Settings |