Title

The RUCKUS ICX switch must have the default VLAN pruned from all trunk ports that do not require it. (Cat II impact)

Discussion

The default VLAN (i.e., VLAN 1) is a special VLAN used for control plane traffic such as Spanning-Tree Protocol (STP), Dynamic Trunking Protocol (DTP), VLAN Trunking Protocol (VTP), and Port Aggregation Protocol (PAgP). VLAN 1 is enabled on all trunks and ports by default. With larger campus networks, care needs to be taken about the diameter of the STP domain for the default VLAN. Instability in one part of the network could affect the default VLAN, thereby influencing control-plane stability and therefore STP stability for all other VLANs.

Check Content

Review the switch configuration and verify that the default VLAN is pruned from trunk links that do not require it. device#show vlan 888 PORT-VLAN 888, Name DEFAULT-VLAN, Priority level0, On Untagged Ports: (U1/M1) 1 2 3 4 5 6 7 8 9 10 11 12 Untagged Ports: (U1/M1) 13 14 15 16 17 18 19 20 21 22 23 24 Untagged Ports: (U1/M1) 25 26 27 28 29 30 31 32 33 34 35 36 Untagged Ports: (U1/M1) 37 38 39 40 41 43 44 45 46 47 48 Untagged Ports: (U1/M2) 1 2 3 4 5 6 7 8 Tagged Ports: None Mac-Vlan Ports: None Monitoring: Disabled device# If the default VLAN is not pruned from trunk links that should not be transporting frames for the VLAN, this is a finding.

Fix Text

Prune unnecessary trunk links from access to the default VLAN. 1. Review the default VLAN ports. device#show vlan 888 PORT-VLAN 888, Name DEFAULT-VLAN, Priority level0, On Untagged Ports: (U1/M1) 1 2 3 4 5 6 7 8 9 10 11 12 Untagged Ports: (U1/M1) 13 14 15 16 17 18 19 20 21 22 23 24 Untagged Ports: (U1/M1) 25 26 27 28 29 30 31 32 33 34 35 36 Untagged Ports: (U1/M1) 37 38 39 40 41 43 44 45 46 47 48 Untagged Ports: (U1/M2) 1 2 3 4 5 6 7 8 2. Remove any trunk ports (example 1/2/1 below) on the list. device(config-vlan-888)# no untag ethernet 1/2/1

Additional Identifiers

Rule ID: SV-273690r1110993_rule

Vulnerability ID: V-273690

Group Title: SRG-NET-000512-L2S-000009

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.