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IP Addressing Plan - Company changing continously!!!


As mentioned previously I have been trying desperately to come up with an IP plan... problem is the company where I am at is so fluid it is unbelievable and is probably the the reason this has not been done and implemented...

Originally there were two main sites with several buildings, and a few remote sites...

My initial plan was to as main site 1 (Using 10.x.0.0 per building)

Then to as main site 2 (Using 10.x.0.0 per building).

Then to as remote site 1 (Single building)

Then to as remote site 2 (Single building)

Then to as remote site 3 (Single building)

I went with this because although there is lots of IP wastage it is clear and easy to understand and aids tracing of devices. As well as this there is lots of space for different VLAN's within each building to break things out into to isolate.

Currently there are only a maximum of 14 buildings in each of the main sites, so using to leaves me plenty of space in each area for new buildings... and allows summarization of said areas .

Problem is, I am now being told we are taking on another large site with multiple buildings... Should I be leaving gaps in this design to accomodate things like this?

How do people design networks like this!


IP Addressing Plan - Company changing continously!!!


Honestlly your first attempt at this would make sense, but now there could be more larger buildings.  What I would recommend is keeping the - for the main large buildings broken down and subnetted.  Then start the remote sites at or to make it easy to identify main sites or remote sites.  This will still leave room for growth and fluidity in the company's networks.

Good Luck.



Thanks and Cheers! Kimberly Please remember to rate helpful posts.

IP Addressing Plan - Company changing continously!!!

Here is how we have done our IP addresses and it works great.


Second octet we use for the city

1 = main office

2 = City 1

3 = City 2

and so on..

so let's say you have your main office in New York City it would be 10.1.x.x

next you have an office in Dallas, Tx it would be 10.2.x.x

Third Octet we use for VLAN designations.

1 = network devices (switches and Routers, etc.)

2 = security devices

3 = Misc. servers

4 = SQL servers

5 = Printers

now with this octet we also slip up Voice and data at the access switches by floor. We will use NYC as an example.

For data we start at 100 and VOIP we start at 200 so.....

if we were on the 10th floor the data VLAN would be VLAN 110 and the IP address would be 10.1.110.x

for Voip it would be VLAN 210 and the IP address would be 10.1.210.x

the only issue is if you were on the 55th floor or above as you could not have with a class c mask so what we do there is use 10.1.55.x   we just drop the 2.

so a SQL server in Dallas would be 10.2.4.x and a Application server in NYC would be 10.1.3.x

Now the last octet we use with servers and in the server name. So lets say you have a physcial SQL server in Dallas and we would name it DAL55P04 and it's IP address would be  notice the last octet matches the name and the last number is the VLAN number and the P = Physical. If it was a veritual server the name would be DAL55V04 where V = virtual.

so based on the above you got a call about someone having a problem and you are given the IP address of you know this is a user in NYC on the 23rd floor.


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