Configuring Dynamic ARP InspectionTo enable dynamic ARP inspection, use the following commands.1. Enable DHCP snooping.2. Validate ARP frames against the DHCP snooping binding table.INTERFACE VLAN modearp inspectionExample of Viewing the ARP DatabaseExample of Viewing ARP PacketsTo view entries in the ARP database, use the show arp inspection database command.Dell#show arp inspection databaseProtocol Address Age(min) Hardware Address Interface VLAN CPU---------------------------------------------------------------------Internet 10.1.1.251 - 00:00:4d:57:f2:50 Te 0/2 Vl 10 CPInternet 10.1.1.252 - 00:00:4d:57:e6:f6 Te 0/1 Vl 10 CPInternet 10.1.1.253 - 00:00:4d:57:f8:e8 Te 0/3 Vl 10 CPInternet 10.1.1.254 - 00:00:4d:69:e8:f2 Te 0/50 Vl 10 CPDell#To see how many valid and invalid ARP packets have been processed, use the show arp inspectionstatistics command.Dell#show arp inspection statisticsDynamic ARP Inspection (DAI) Statistics---------------------------------------Valid ARP Requests : 0Valid ARP Replies : 1000Invalid ARP Requests : 1000Invalid ARP Replies : 0Dell#Bypassing the ARP InspectionYou can configure a port to skip ARP inspection by defining the interface as trusted, which is useful inmulti-switch environments.ARPs received on trusted ports bypass validation against the binding table. All ports are untrusted bydefault.To bypass the ARP inspection, use the following command.• Specify an interface as trusted so that ARPs are not validated against the binding table.INTERFACE modearp inspection-trustDell Networking OS Behavior: Introduced in Dell Networking OS version 8.2.1.0, DAI was available forLayer 3 only. However, Dell Networking OS version 8.2.1.1 extends DAI to Layer 2.268 Dynamic Host Configuration Protocol (DHCP)
