SMC Networks Barricade SMC7401BRA User Manual page 57

Configuring Dynamic Host Configuration Protocol
You can create up to two pools. The pools can maintain a
combined total of 254 IP addresses. For example, you can
configure only one pool with addresses in the range 192.168.1.2
through 192.168.1.255, or two pools with the following address
ranges:
Pool 0: 192.168.1.2 through 192.168.1.128
Pool 1: 192.168.1.129 through 192.168.1.255
The same pool can be used for distributing IP addresses to your
LAN PCs (connected via the Ethernet port), as long as these
ports are in the same subnet. You may want to create a second
pool if any of these circumstances apply:
•
If a USB port is provided in the device, its Ethernet (eth-0) and
USB (usb-0) ports are in different subnets (note that different
subnets are not required). See IP Addresses, Network Masks
and Subnets on page 173 for an explanation of subnets.
•
Your LAN configuration includes two subnets.
•
You have only one subnet, but the addresses you want to
distribute are not in a continuous range. (Alternatively, you
can exclude particular addresses from distribution from a
single pool; see page 56.)
The DHCP server will distribute addresses to the computers
connected to a given device interface only when that interface is
in the same subnet as the pool addresses. For example, assume
that the Ethernet and USB interfaces are assigned IP addresses
that place them in two different subnets, as shown:
Ethernet interface (eth-0): IP address
USB interface (usb-0):
52
mask
IP address
mask
192.168.1.1
255.255.255.0
192.168.2.1
255.255.255.0