3Com 10014299 manual Configure Dhcp relay router

Configure DHCP Relay 347

II. Networking Diagram

Figure 128 Networking diagram of an DHCP relay configuration example

DHCP client host

10.110.1.1

DHCP trunk router

Intermediate
network	DHCPserver
	202.38.160.2
202.38.160.1

III.Configuration Procedure

1 Configure DHCP relay router:

[Router-Ethernet0]ip address 10.110.1.1 255.255.0.0

[Router-Ethernet0]ip relay-address 202.38.160.2

To configure helper address 202.38.160.2 on the Ethernet interface 0 you need to specify the address for the DHCP server. When requesting for configuration information, the DHCP client host sends out a DHCP broadcast message. After receiving the broadcast message, the Ethernet interface of the DHCP relay router processes and sends it to the helper address of the interface, i.e. the DHCP server. The DHCP server returns the generated reply message to the DHCP relay router, then the router notifies the DHCP client host of the reply message.

Configuration example of transparent transmission forwarding protocol

I. Configuration Requirements

The host and TFTP server should not be in the same network segment. As the host does not know the IP address of TFTP server, it sends a request message with the broadcast address as the destination address so as to transmit it transparently to the TFTP server via router A.