Cabletron Systems 9032578-05 manual Configuring Secondary Subnets

Chapter 7: DHCP Configuration Guide

9.Specify a remote lease database on the TFTP server 10.1.89.88.

dhcp global set lease-database tftp://10.1.89.88/lease.db

10.Specify a database update interval of every 15 minutes.

dhcp global set commit-interval 15

Configuring Secondary Subnets

In some network environments, multiple logical subnets can be imposed on a single physical segment. These logical subnets are sometimes referred to as “secondary subnets” or “secondary networks.” For these environments, the DHCP server may need to give out addresses on different subnets. The DNS server, DNS domain, and WINS server may be the same for clients on different secondary subnets, however, the default gateway will most likely be different since it must be a router on the client’s local subnet.

The following example shows a simple configuration to support secondary subnets 10.1.x.x and 10.2.x.x.

1.Define the network parameters for ‘scope1’ with the default gateway 10.1.1.1.

dhcp scope1 define parameters address-netmask 10.1.0.0/16 gateway

10.1.1.1dns-domain acme.com dns-server 10.1.44.55

2.Define the address pool for ‘scope1’.

dhcp scope1 define pool 10.1.1.10-10.1.1.20

3.Define the network parameters for ‘scope2’ with the default gateway 10.2.1.1.

dhcp scope2 define parameters address-netmask 10.2.0.0/16 gateway

10.2.1.1dns-domain acme.com dns-server 10.1.77.88

4.Define the address pool for ‘scope2’.

dhcp scope2 define pool 10.2.1.40-10.2.1.50

5.Create a superscope ‘super1’ that includes ‘scope1’.

dhcp scope1 attach superscope super1

72 SmartSwitch Router User Reference Manual