JUEX-L2-000080 - The Juniper EX switch must be configured to enable Root Protection on all interfaces connecting to access layer switches and hosts.

Information

Spanning Tree Protocol (STP) does not provide any means for the network administrator to securely enforce the topology of the switched network. Any switch can be the root bridge in a network. However, a more optimal forwarding topology places the root bridge at a specific predetermined location. With the standard STP, any bridge in the network with a lower bridge ID takes the role of the root bridge. The administrator cannot enforce the position of the root bridge but can set the root bridge priority to 0 in an effort to secure the root bridge position.

The Root Protection feature provides a way to enforce the root bridge placement in the network. If the bridge receives superior STP Bridge Protocol Data Units (BPDUs) on a Root Protection-enabled interface, Root Protection ignores the superior BPDU and places the interface into block and a root-inconsistent state. To enforce the position of the root bridge it is imperative that Root Protection is enabled on all interfaces where the root bridge should never appear.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

Solution

Configure the switch to have Root Protection enabled on all switch ports connecting to access layer switches and hosts using trunked interfaces.

set protocols mstp interface <interface name> no-root-port

Note: Root Protection and Loop Protection are mutually exclusive and cannot be simultaneously configured on the same interface.

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_Juniper_EX_Switches_Y24M07_STIG.zip

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-5, CAT|III, CCI|CCI-002385, Rule-ID|SV-253955r843898_rule, STIG-ID|JUEX-L2-000080, Vuln-ID|V-253955

Plugin: Juniper

Control ID: d06ab3accddae73bca1357eebad474bdc875abc86fa8b048df692914959188f1