Dynamic Host Configuration Protocol (DHCP) is a service that runs at the application layer of the TCP/IP protocol stack to dynamically assign IP addresses to DHCP clients, and to allocate TCP/IP configuration information to DHCP clients. DHCP messages are broadcast messages which cannot cross from one network to another. DHCP Interface settings require the configuration of the DHCP relay and DHCP snooping which are explained below.
DHCP relay forwards the broadcast messages to a different network. It also adds option 82 to provide additional information of the client to the routing network.
DHCP snooping helps to identify trusted interfaces from untrusted ones. It prevents false DHCP responses. In layer 3 switches, DHCP relay and snooping can be enabled on any interface with an IP address and on VLAN with or without an IP address.
The document explains how to configure DHCP Interface settings on ESW2-350G switches.
Note: You have to enable DHCP relay before you proceed. For more information refer to the article entitled DHCP Properties Configuration on ESW2-350G Switches.
• ESW2-350G • ESW2-350G-DC
Configure DHCP Interface settings
Step 1. Log in to the switch configuration utility to choose IP Configuration >DHCP > Interface Settings. The Interface Settings page opens.
Step 2. Click Add to add an interface configuration. A new window appears as follows:
Step 3. From the Interface drop-down list choose a particular VLAN to which to apply DHCP settings.
Step 4. (Optional) Check the DHCP Relay check box to enable DHCP relay on the VLAN.
Step 5. (Optional) Check the DHCP Snooping check box to enable DHCP snooping on the VLAN.