Dell Force10 S4820T S4820T Configuration Guide - Page 357

Use show arp inspection statistics command to see how many valid and invalid ARP packets have been processed. FTOS#show arp inspection statistics Dynamic ARP Inspection (DAI) Statistics Valid ARP Requests Valid ARP Replies Invalid ARP Requests Invalid ARP Replies FTOS# : 0 : 1000 : 1000 : 0 Bypass the ARP Inspection You can configure a port to skip ARP inspection by defining the interface as trusted, which is useful in multi-switch environments. ARPs received on trusted ports bypass validation against the binding table. All ports are untrusted by default. Task Specify an interface as trusted so that ARPs are not validated against the binding table. Command Syntax arp inspection-trust Command Mode INTERFACE FTOS Behavior: Introduced in FTOS version 8.2.1.0, Dynamic ARP Inspection (DAI) was available for Layer 3 only. FTOS version 8.2.1.1 extends DAI to Layer 2. Source Address Validation Using the DHCP binding table, FTOS can perform three types of source address validation (SAV): • IP Source Address Validation prevents IP spoofing by forwarding only IP packets that have been validated against the DHCP binding table. • DHCP MAC Source Address Validation verifies a DHCP packet's source hardware address matches the client hardware address field (CHADDR) in the payload. • IP+MAC Source Address Validation verifies that the IP source address and MAC source address are a legitimate pair. IP Source Address Validation IP Source Address Validation (SAV) prevents IP spoofing by forwarding only IP packets that have been validated against the DHCP binding table. A spoofed IP packet is one in which the IP source address is strategically chosen to disguise the attacker. For example, using ARP spoofing an attacker can assume a legitimate client's identity and receive traffic addressed to it. Then the attacker can spoof the client's IP address to interact with other clients. Dynamic Host Configuration Protocol (DHCP) | 357