DHCP MAC Source Address ValidationDHCP MAC source address validation (SAV) validates a DHCP packet’s source hardware address against the client hardwareaddress field (CHADDR) in the payload.Dell Networking OS ensures that the packet’s source MAC address is checked against the CHADDR field in the DHCP header onlyfor packets from snooped VLANs.• Enable DHCP MAC SAV.CONFIGURATION modeip dhcp snooping verify mac-addressEnabling IP+MAC Source Address ValidationIP source address validation (SAV) validates the IP source address of an incoming packet and optionally the VLAN ID of the clientagainst the DHCP snooping binding table. IP+MAC SAV ensures that the IP source address and MAC source address are a legitimatepair, rather than validating each attribute individually. You cannot configure IP+MAC SAV with IP SAV.1. Allocate at least one FP block to the ipmacacl CAM region.CONFIGURATION modecam-acl l2acl2. Save the running-config to the startup-config.EXEC Privilege modecopy running-config startup-config3. Reload the system.EXEC Privilegereload4. Do one of the following.• Enable IP+MAC SAV.INTERFACE modeip dhcp source-address-validation ipmac• Enable IP+MAC SAV with VLAN option.INTERFACE modeip dhcp source-address-validation ipmac vlan vlan-idDell Networking OS creates an ACL entry for each IP+MAC address pair and optionally with its VLAN ID in the binding table andapplies it to the interface.To display the IP+MAC ACL for an interface for the entire system, use the show ip dhcp snooping source-address-validation [interface] command in EXEC Privilege mode.Viewing the Number of SAV Dropped PacketsThe following output of the show ip dhcp snooping source-address-validation discard-counters commanddisplays the number of SAV dropped packets.Dell>show ip dhcp snooping source-address-validation discard-countersdeny access-list on TenGigabitEthernet 1/1Total cam count 1deny count (0 packets)deny access-list on TenGigabitEthernet 1/2Dynamic Host Configuration Protocol (DHCP) 237
