Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 340

• DHCP Snooping is supported only FOR SPANNED VLANs. • Source address validation is not supported for VPLAG interfaces on VLT. • Port Extender does not support DHCP server. Prerequisites for DHCP Snooping • DHCP Snooping should be enabled globally on both VLT peers. • The same Remote ID string and Remote ID host name should be configured on both VLT peers. • To enable DHCP Secondary subnet feature in VLT, ensure that the secondary IP address subnet is the same in both VLT peers. • Apply similar dynamic ARP inspection and source address validation configurations on both VLT peers. • If you want to use the clear ip dhcp snooping binding command, use it individually on VLT nodes. • In a dual-homed setup, you cannot configure DHCP snooping using batch mode. You can configure DHCP snooping separately on each VLT peer. • In the event of snooping VLAN operation down or interface delete, the removal of snooping binding entries is not synchronized to the VLT peer . Enabling DHCP Snooping To enable DHCP snooping, use the following commands. 1 Enable DHCP snooping globally. CONFIGURATION mode ip dhcp snooping 2 Specify ports connected to DHCP servers as trusted. INTERFACE mode ip dhcp snooping trust 3 Enable DHCP snooping on a VLAN. CONFIGURATION mode ip dhcp snooping vlan name Adding a Static Entry in the Binding Table To add a static entry in the binding table, use the following command. • Add a static entry in the binding table. EXEC mode EXEC Privilege mode ip dhcp snooping binding mac Clearing the Binding Table To clear the binding table, use the following command. • Delete all of the entries in the binding table. EXEC Privilege mode clear ip dhcp snooping binding Dynamic Host Configuration Protocol (DHCP) 340