The Cisco perimeter switch must be configured to have Link Layer Discovery Protocol (LLDP) disabled on all external interfaces.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-221096 | CISC-RT-000360 | SV-221096r999705_rule | CCI-002403 | low |
| Description | ||||
| LLDP is a neighbor discovery protocol used to advertise device capabilities, configuration information, and device identity. LLDP is media-and-protocol-independent as it runs over layer 2; therefore, two network nodes that support different layer 3 protocols can still learn about each other. Allowing LLDP messages to reach external network nodes provides an attacker a method to obtain information of the network infrastructure that can be useful to plan an attack. | ||||
| STIG | Date | |||
| Cisco NX OS Switch RTR Security Technical Implementation Guide | 2024-12-20 | |||
Details
Check Text (C-221096r999705_chk)
Step 1: Verify LLDP is not enabled globally via the command feature lldp.
By default the LLDP feature is not enabled. If LLDP is enabled, proceed to Step 2.
Step 2: Verify LLDP is not enabled on any external interface as shown in the example below:
interface Ethernet2/2
description link to DISN
no switchport
no lldp transmit
Note: LLDP is enabled by default on all interfaces once it is enabled globally; hence the command lldp transmit will not be visible on the interface configuration.
If LLDP transmit is enabled on any external interface, this is a finding.
Fix Text (F-22800r409778_fix)
Disable LLDP transmit on all external interfaces as shown in the example below:
SW2(config)# int e2/2
SW2(config-if)# no lldp transmit
SW2(config-if)# end