Users Guide

NOTE: If you enable IP source guard using the ip dhcp source-address-validation command and if there are more
entries in the current DHCP snooping binding table than the available CAM space, SAV may not be applied to all entries. To
ensure that SAV is applied correctly to all entries, enable the ip dhcp source-address-validation command before
adding entries to the binding table.
• Enable IP source address validation.
INTERFACE mode
ip dhcp source-address-validation
• Enable IP source address validation with VLAN option.
INTERFACE mode
ip dhcp source-address-validation vlan vlan-id
NOTE:
Before enabling SAV With VLAN option, allocate at least one FP block to the ipmacacl CAM region.
DHCP MAC Source Address Validation
DHCP MAC source address validation (SAV) validates a DHCP packet’s source hardware address against the client hardware address eld
(CHADDR) in the payload.
Dell Networking OS ensures that the packet’s source MAC address is checked against the CHADDR eld in the DHCP header only for
packets from snooped VLANs.
• Enable DHCP MAC SAV.
CONFIGURATION mode
ip dhcp snooping verify mac-address
Enabling IP+MAC Source Address Validation
IP source address validation (SAV) validates the IP source address of an incoming packet and optionally the VLAN ID of the client against
the DHCP snooping binding table. IP+MAC SAV ensures that the IP source address and MAC source address are a legitimate pair, rather
than validating each attribute individually. You cannot congure IP+MAC SAV with IP SAV.
1 Allocate at least one FP block to the ipmacacl CAM region.
CONFIGURATION mode
cam-acl l2acl
2 Save the running-cong to the startup-cong.
EXEC Privilege mode
copy running-config startup-config
3 Reload the system.
EXEC Privilege
reload
4 Do one of the following.
• Enable IP+MAC SAV.
INTERFACE mode
ip dhcp source-address-validation ipmac
• Enable IP+MAC SAV with VLAN option.
Dynamic Host
Conguration Protocol (DHCP) 247