Subnetting

[Brian The Snail]

Hello,

I would appreciate you comments on the following. Sorry about the length of the post.

I have one Windows 2000 network (10.0.0.x) with approximately 200 hosts.
The network spans two distant sites (A & B) and is connected by a very slow
connection. Unfortunately cost prohibits us doing anything about this.

What I want to do is split the network into two sites with the main aim of
reducing traffic between the two. To do this I will be putting in a
secondary domain controller at site B to privide authentication and DHCP
services to clients at site B and to provide failover services for site A
(and visa versa for site B). There are also several other servers at site A
which will remain but need to be available to clients at site B. What is
more, I have installed a second phone line at site B to handle the Internet
connectively for that site.

Here is my plan. Can you tell me if this will
a) Allow clients at A or B to see the servers at the other sites
b) Allow failover for A to B or B to A
c) work?

Site A:
Router 10.0.0.1 ???????????
Firewall 10.0.0.x
Servers 10.0.0.x 255.255.254.0
Clients 10.0.0.x 255.255.255.0 Default GW = 10.0.0.1

Site B
Router 10.0.1.1 ???????????
Servers 10.0.1.x 255.255.254.0
Clients 10.0.1.x 255.255.255.0 Default GW = 10.0.1.1
Firewall 10.0.1.x

I really appreciate any advise or help.

Kind regards,
Andy

 

[Chief Wiggum]

Hey Andy,

I'm afraid that won't work.

The subnet mask you've chosen for your servers at Site A Overlaps the clients at Site A and all the networks at Site B.

IP 10.0.0.0 Mask 255.255.254.0 = 10.0.0.0>10.0.1.255 because you've also made no provisions for your routing you'll probably get some weird issues at Site A and Site B for the clients and Servers.

Depending on the size of the network and the routing you have available I'd do this:
Site A >
Main network 10.0.0.0 255.255.254.0
Servers: 10.0.0.0 255.255.255.0
Clients: 10.0.1.0 255.255.255.0

Site B >
Main network 10.0.2.0 255.255.254.0
Servers: 10.0.2.0 255.255.255.0
Clients: 10.0.3.0 255.255.255.0

Now if you didn't have the routing, you could just use the main networks at both sites (for both clients and servers), or if you want to allow for future growth you could expand the mask to 255.255.252.0 which makes the following:

Site A >
Main network 10.0.0.0 255.255.252.0
Servers: 10.0.0.0 255.255.255.0
Clients: 10.0.1.0 255.255.255.0
Expansion1: 10.0.2.0 255.255.255.0
Expansion2: 10.0.3.0 255.255.255.0

Site B >
Main network 10.0.4.0 255.255.252.0
Servers: 10.0.5.0 255.255.255.0
Clients: 10.0.5.0 255.255.255.0
Expansion1: 10.0.6.0 255.255.255.0
Expansion2: 10.0.7.0 255.255.255.0

Kev

 

[Brian The Snail]

Many thanks for the reply Chief Wiggum.