HELP : How to group IP addresses by refering to them as a single name ?

[Alok Shukla <alokshukla@yahoo.com>]

HI,

I run a College Laboratory with two rooms for the
whole labaratory
I have given a static IP for each of the computers
from 192.168.0.1 to 192.168.0.254.

1. My Lab 1 has IP from 192.198.0.11 to 192.168.0.50
and Lab 2 has IP from 192.168.0.51 to 192.168.0.90

2. I run a Redhat Linux 7.3 Server that acts as a
masquerading server, DNS Server and a Web Server.Its
IP is 192.168.0.1

3. I also have Windows NT Server for running a domain
over the whole network.Its IP is 192.168.0.2

4. My each of the client machine has Windows XP
Professional running which acts as a CLient for WIN NT
Domain.Each computer has gateway setting as for Red
Hat Linux 7.3 machine.

5. My Iptables scripts allows everbody to access the
net through following command:-

iptables -t nat -A POSTROUTING -s 192.168.0.0/24 -d
any/0 -j MASQUERADE

Now my problem :-

I want to have a set of rules so that i can group Lab
1 computers in one group and Lab 2 computers in
another group. In this I want to able to shutdown the
Internet facility by stopping its masquerading as a
whole by refering as a single name.

Like something like :-

iptables -t nat -D POSTROUTING -s "LAB1" -d any/0 -J
MASQUERADE

or rather

iptables -t nat -D POSTROUTING -s 192.168.0.11-50  -d
any/0 -J MASQUERADE

Is short i want to create groups and i want to
administer network access by refering to group of
computers rather than their respective IP addresses..
SOmething like name addressing or rather multicasting 
etc...or whatever

Alok Shukla

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