The Cisco switch must be configured to have gratuitous ARP disabled on all external interfaces.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-220431 | CISC-RT-000150 | SV-220431r856233_rule | CCI-002385 | medium |
| Description | ||||
| A gratuitous ARP is an ARP broadcast in which the source and destination MAC addresses are the same. It is used to inform the network about a host IP address. A spoofed gratuitous ARP message can cause network mapping information to be stored incorrectly, causing network malfunction. | ||||
| STIG | Date | |||
| Cisco IOS Switch RTR Security Technical Implementation Guide | 2024-06-06 | |||
Details
Check Text (C-220431r856233_chk)
Review the configuration to determine if gratuitous ARP is disabled. The following command should not be found in the switch configuration:
ip gratuitous-arps
Note: With Cisco IOS, gratuitous ARP is enabled and disabled globally.
If gratuitous ARP is enabled on any external interface, this is a finding.
Fix Text (F-22135r508379_fix)
Disable gratuitous ARP as shown in the example below:
SW1(config)#no ip gratuitous-arps