The Dell OS10 Switch must have Dynamic Address Resolution Protocol (ARP) Inspection (DAI) enabled on all user VLANs.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-269961	SRG-NET-000362-L2S-000027	OS10-L2S-000150	SV-269961r1052492_rule	2024-12-11	1

Description
DAI intercepts ARP requests and verifies that each of these packets has a valid IP-to-MAC address binding before updating the local ARP cache and before forwarding the packet to the appropriate destination. Invalid ARP packets are dropped and logged. DAI determines the validity of an ARP packet based on valid IP-to-MAC address bindings stored in the DHCP snooping binding database. If the ARP packet is received on a trusted interface, the switch forwards the packet without any checks. On untrusted interfaces, the switch forwards the packet only if it is valid.

Description

DAI intercepts ARP requests and verifies that each of these packets has a valid IP-to-MAC address binding before updating the local ARP cache and before forwarding the packet to the appropriate destination. Invalid ARP packets are dropped and logged. DAI determines the validity of an ARP packet based on valid IP-to-MAC address bindings stored in the DHCP snooping binding database. If the ARP packet is received on a trusted interface, the switch forwards the packet without any checks. On untrusted interfaces, the switch forwards the packet only if it is valid.

ℹ️ Check
Review the switch configuration to verify that DAI feature is enabled on all user VLANs. Verify that each user VLAN has arp inspection enabled. ! interface vlan200 no shutdown arp inspection ! interface vlan201 no shutdown arp inspection If ARP inspection is not enabled on all user VLANs, this is a finding.

✔️ Fix
Configure the switch to have DAI enabled on all user VLANs as shown in the example below: OS10(config)# interface range vlan 200-201 OS10(conf-range-vl-200-201)# arp inspection