The Juniper router must be configured to have Gratuitous ARP disabled on all external interfaces.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-254032 | JUEX-RT-000600 | SV-254032r844129_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 | |||
| Juniper EX Series Switches Router Security Technical Implementation Guide | 2024-06-10 | |||
Details
Check Text (C-254032r844129_chk)
Review the configuration to determine if gratuitous ARP is disabled on all external interfaces.
[edit interfaces]
<external interface> {
no-gratuitous-arp-reply;
no-gratuitous-arp-request;
unit <number> {
family inet {
address <IPv4 address>/<mask>;
}
family inet6 {
address <IPv6 address>/<mask>;
}
}
}
If gratuitous ARP is enabled on any external interface, this is a finding.
Fix Text (F-57435r844128_fix)
Disable gratuitous ARP on all external interfaces.
set interfaces <external interface> no-gratuitous-arp-reply
set interfaces <external interface> no-gratuitous-arp-request
set interfaces <external interface> unit <number> family inet address <IPv4 address>/<mask>
set interfaces <external interface> unit <number> family inet6 address <IPv6 address>/<prefix>