Chapter 6 DHCP Server Setup
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6.4 DHCP Relay Setup
Deploying DHCP in a single subnet network is straightforward. DHCP messages are IP broadcast
messages, and all computers on the subnet can listen to and respond to these broadcasts. A single DHCP
server is all that is required.
Things become more complicated when you have more than one subnet on your network. This is because
the DHCP broadcast messages do not (by default) cross the router interfaces. The DHCP relay agent
allows you to place DHCP Clients and DHCP Servers on different subnets of your network or even to put
them on different networks.
After setting up a DHCP Server, it is quite easy to add a DHCP Relay Server as shown in Figure 6-2, below.
IP Network
LAN1
WAN1
DHCP Relay Server
..........
Loop-IP
6610
Loop-IP
6610
DHCP Server
IP Address: 10.3.2.10
Figure 6-2 DHCP Relay Setup
To set up the DHCP relay server, you must first set up the DHCP Server and then use the commands in
Table 6-2, below. Step by step instructions follow the table.
Table 6-2 DHCP Relay Admin Commands
DHCP Relay Admin Commands
Commands Parameters Description
server ip address specify an IP 6610 unitas a DHCP relay
server
set dhcp