Dell PowerConnect 6248 User's Guide - Page 447

The hardware identifies all incoming DHCP packets on ports where DHCP snooping is enabled. DHCP snooping is enabled on a port if (a) DHCP snooping is enabled globally, and (b) the port is a member of a VLAN where DHCP snooping is enabled. On untrusted ports, the hardware traps all incoming DHCP packets to the CPU. On trusted ports, the hardware forwards client messages and copies server messages to the CPU so that DHCP snooping can learn the binding. Table 7-64. DHCP Snooping Trusted Port Destination UDP Port 67 (from client) Forward in hardware Untrusted Port Trap to CPU (enforcement) Destination UDP Port 68 (from server) Copy to CPU (Complete the tentative binding for a given DHCP client, based on the MAC address.) Trap to CPU (error logging) To display the DHCP Snooping page, click Switching →DHCP Snooping in the tree view. The DHCP Snooping menu page contains links to the following features: • DHCP Snooping Configuration • DHCP Snooping Interface Configuration • DHCP Snooping VLAN Configuration • DHCP Snooping Persistent Configuration • DHCP Snooping Static Bindings Configuration • DHCP Snooping Dynamic Bindings Summary • DHCP Snooping Statistics DHCP Snooping Configuration Use the DHCP Snooping Configuration page to control the DHCP Snooping mode on the switch and to specify whether the sender MAC Address for DHCP Snooping must be validated. To access the DHCP Snooping Configuration page, click Switching →DHCP Snooping →Global Configuration in the navigation tree. Configuring Switching Information 447