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V-273686

CAT II (Medium)

The RUCKUS ICX switch must implement Rapid Spanning Tree Protocol (STP) where VLANs span multiple switches with redundant links.

Rule ID

SV-273686r1110989_rule

STIG

RUCKUS ICX Layer 2 Switch Security Technical Implementation Guide

Version

V1R1

CCIs

CCI-000366

Discussion

STP is implemented on bridges and switches to prevent layer 2 loops when a broadcast domain spans multiple bridges and switches and when redundant links are provisioned to provide high availability in case of link failures. Convergence time can be significantly reduced using Rapid STP (802.1w) instead of STP (802.1d), resulting in improved availability. Rapid STP should be deployed by implementing either Rapid Per-VLAN-Spanning-Tree (Rapid-PVST) or Multiple Spanning-Tree Protocol (MSTP), the latter scales much better when there are many VLANs.

Check Content

Review configuration for VLANs that are not set for 802.1w (Rapid Spanning Tree).  

vlan 10 name testing by port
 tagged ethernet 1/1/17
 untagged ethernet 1/1/18
 spanning-tree 802-1w
!

If 802.1w is not configured on VLANs that span multiple switches with redundant links, this is a finding.

Fix Text

Configure Rapid STP at the access and distribution layers where VLANs span multiple switches.

VLAN:
Router# configure terminal
Router (config)# vlan 10 
Router(config-vlan-10)#spanning-tree 802-1w 
(config-vlan-10)# spanning-tree 802-1w priority 256 

Optional Per Port:
Router#configure terminal
Router(config) interface ethernet 1/1/1 
Router(config-if-e2500-1/1/1) spanning-tree 802-1w admin-pt2pt-mac 
<OR> 
spanning-tree 802-1w admin-edge-port