IP Numbering Plan

[estone4009]

Currently have a local Lan with about 60 users all using manual IP's and using NAT through a sonicwall for internet access. We will be adding six new locations with about 200 users using Cisco MC3810 routers. We want the LAN to be seamless for everyone. My current internal numbering scheme is IP 10.1.1.(1-60) with a subnet mask of 255.255.255.0. How do I need to set it up where each location can become 10.1.2.(1-254). Basically what has to be done to the subnet mask and does it need to be changed on every machine?

 

[highs008]

I would suggest using the following IP-scheme:

|----+------------------| <- subnet A
|
+----+-----+
| ROUTER 1 +
+----+-----+
|
|
{ TELCO } --------+-------------+
| | |
| | |
| | |
+----+-----+ +----------+ +----+-------+
| ROUTER 2 + | ROUTER 3 + | ROUTER +
+----+-----+ +----+-----+ +----+-------+
| | |
| | |----+----| SUBNET n
| |----+----| <- subnet C
|----+----| <- subnet B


SUBNET LOCATION IP-NETWORK SUBNET-MASK
---------------------------------------------------
A Current IP Network 10.1.1.x 255.255.255.0
B new 10.1.2.x 255.255.255.0
C new 10.1.3.x 255.255.255.0
n new and so on 255.255.255.0

TELCO in this example is your telecom provider. I would not suggest to use 10.1.2.x for every new location. In this situation you don't have to change your subnet mask.