Dell PowerSwitch S4820T 9.50.1 Configuration Guide for the S4820T System - Page 328

is exhausted, DHCP packets are dropped on snooped VLANs, while these packets are forwarded across non-snooped VLANs. Because DHCP packets are dropped, no new IP address assignments are made. However, DHCPRELEASE and DHCPDECLINE packets are allowed so that the DHCP snooping table can decrease in size. After the table usage falls below the maximum limit of 4000 entries, new IP address assignments are allowed. NOTE: DHCP server packets are dropped on all not trusted interfaces of a system configured for DHCP snooping. To prevent these packets from being dropped, configure ip dhcp snooping trust on the server-connected port. 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 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 Displaying the Contents of the Binding Table To display the contents of the binding table, use the following command. • Display the contents of the binding table. EXEC Privilege mode show ip dhcp snooping 328 Dynamic Host Configuration Protocol (DHCP)