Check: CISC-RT-000150
Cisco NX OS Switch RTR STIG:
CISC-RT-000150
(in versions v2 r3 through v1 r0.1)
Title
The Cisco switch 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 on all external interfaces as shown in the example below: interface Ethernet2/7 no switchport ip address x.22.4.2/30 no ip arp gratuitous request Note: Gratuitous ARP is enabled on all interfaces by default. If gratuitous ARP is enabled on any external interface, this is a finding.
Fix Text
Disable Gratuitous ARP as shown in the example below: SW1(config)# int e2/7 SW1(config-if)# no ip arp gratuitous request SW1(config-if)# end
Additional Identifiers
Rule ID: SV-221082r856635_rule
Vulnerability ID: V-221082
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 |