Check: CISC-RT-000150
Cisco IOS XE Router RTR STIG:
CISC-RT-000150
(in versions v2 r9 through v1 r1)
Title
The Cisco router must be configured to have Gratuitous ARP disabled on all external interfaces. (Cat II impact)
Discussion
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.
Check Content
Review the configuration to determine if gratuitous ARP is disabled. The following command should not be found in the router 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
Disable gratuitous ARP as shown in the example below: R5(config)#no ip gratuitous-arps
Additional Identifiers
Rule ID: SV-216653r855814_rule
Vulnerability ID: V-216653
Group Title: SRG-NET-000362-RTR-000111
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-002385 |
The information system protects against or limits the effects of organization-defined types of denial of service attacks by employing organization-defined security safeguards. |
Controls
Number | Title |
---|---|
SC-5 |
Denial Of Service Protection |