Switch 7700 Configuration Guide

52 CHAPTER 4: NETWORK PROTOCOL OPERATION

Figure 2 DHCP Relay Schematic Diagram

When the DHCP Client performs initialization, it broadcasts the request packet on

the local network segment. If there is a DHCP server on the local network segment

(e.g. the Ethernet on the right side of the figure), then the DHCP can be

configured directly without the relay. If there is no DHCP server on the local

network segment, the DHCP relay will process the received broadcast packets and

forward them to DHCP remote servers. The server configures the Clients-Server

according to the information provided by it and transmits the configuration

information to the clients through the DHCP relay, thereby completing the

dynamic configuration for the Client.

Configuring DHCP Relay DHCP relay configuration includes:

■ Configures the corresponding DHCP Server IP Address of a DHCP Server

■ Configures Corresponding DHCP Server Group of the VLAN Interface

■ Configurse the Address Table Entry

■ Enables DHCP security features

■ Configures DHCP broadcast packets snooping function on the switch

(supported by the Layer 2 products S3000/S2000.)

Configure the Corresponding DHCP Server IP Address of a DHCP Server

Perform the following configuration in System view.

Note: The backup server IP address cannot be configured independently, instead,

it has to be configured together with the master server IP address.

The corresponding IP address of the DHCP Server is not configured by default. The

DHCP Server address must be configured before DHCP relay can be used.

DHCP clients

Switch

Intranet

DHCP client

DHCP server

Ethernet

Tab le 6 Configure/Delete the IP Address of the DHCP Server

Operation Command

Configure the IP address of the

DHCP Server

dhcp-server groupNo ip ipaddress1 [ ipaddress2 ]

Remove all the IP addresses of

the DHCP Server (namely, set

the IP addresses of the primary

and secondary servers to 0).

undo dhcp-server groupNo