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-221016 | CISC-RT-000360 | SV-221016r856411_rule | 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 IOS XE Switch RTR Security Technical Implementation Guide | 2023-09-13 |
Details
| Check Text ( C-22731r408842_chk ) |
|---|
| Step 1: Verify LLDP is not enabled globally via the command. lldp run By default LLDP is not enabled globally. 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 GigabitEthernet0/1 ip address x.1.12.1 255.255.255.252 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-22720r408843_fix) |
|---|
| Disable LLDP transmit on all external interfaces as shown in the example below: SW1(config)#int g0/1 SW1(config-if)#no lldp transmit |