Ip address plan. How is your network setup?

[dany2010]

Hi,

 

At the minute there is no real rules on what ip address should be given to devices so I would like to get one sorted.

 

Has anyone got a document that says what ip address ranges should be used for different devices?

 

Many thanks.

Edited February 26, 2012 by dany2010

[EduTech]

There is not really any set rules to tell you what IP Address you should give a device. Do you have a Single IP Range? I.e. 10.10.10.1 - 10.10.10.254?

 

Example:

 

10.10.10.1 - 10.10.10.25 = Servers

10.10.10.26 - 10.10.10.210 = Desktops

10.10.10.211 - 10.10.10.220 = Printers

10.10.10.221 - 10.10.10.250 = ANYTHING

10.10.10.254 = Gateway (Generally)

 

^ that is for small networks, if you are working in a school or large network i would expect you to maybe use VLAN's etc. so you would have the following (depending on how many devices you have in your network, and what type this is going to vary and won't be accurate)

 

10.10.1.x = Servers

10.10.2.x = Desktops/Notebooks

10.10.3.x = Desktops/Notebooks

10.10.4.x = Desktops/Notebooks

10.10.5.x = WIFI?

10.10.5.x = Printers

etc.

 

James.

Edited February 26, 2012 by EduTech
change to fall in-line with recommendation below. ;-) keeps it simple

[m25man]

There are no rules.

Class A, B or C you choose the most applicable to your needs and routing requirements.

 

Just avoid some of the more common combinations so as not to invoke conflicts further down the line.

Eg. most home routers use 192.168.0.xxx as an IP range if you choose 192.168.0.xxx as your school or business LAN you will have the same subnet and this can give rise to issues with features like VPN's

 

If you are part of an LEA managed group you should work within the guidelines of the LEA's routing plan. Seek advice from them before making changes you may live to regret.

 

I look after many LANs like this so I make sure ours is on something different so as to avoid such issues.

 

Never use Public IP addresses internally other than in a DMZ or routed mode.

 

Apart from that your more or less free to do as you will.

[pritchardavid]

An example how I have set ours up (example, not real data of course)

 

Switches 10.140.81.1 - 10.140.81.50 (we only have 40 switches, I have left 10 IP addresses spare we of course can be increased at a later date if ever needed)

 

Wirless Routors 10.140.82.1 - 10.140.82.30 (we only have 20 wireless routors, I have left 10 IP addresses spare we of course can be increased at a later date if ever needed)

 

Printers 10.140.83.1 - 10.140.83.30 (we only have 20 printers, I have left 10 IP addresses spare we of course can be increased at a later date if ever needed)

 

Servers 10.140.84.1 - 10.140.84.30 (we only have 25 servers, I have left 5 IP addresses spare we of course can be increased at a later date if ever needed)

 

IP Cameras 10.140.85.1 - 10.140.85.30 (we only have 25 printers, I have left 5 ip addresses spare we of course can be increased at a later date if ever needed)

 

 

-----------------------------------------------

The range for example 'servers' have the range 10.140.84.1 to 10.140.84.30 excluded form the DHCP scope so no DHCP client can take any of the IP adderess used in that range. The exclusion range can be increased if you get more devices than you have in the original exclusion range.

 

This is done the same way for each type of networked devices. Having lots of different ranges are better in my opinion because you can expand better. If you just one range for example 10.140.81.1 to 10.140.81.254 and want to keep the same type of devices together you might over lap the devices IP address at one point, doing it there own range allows you to expand without any worry.

 

All our DHCP clients then just you the DHCP scope to get any IP addresses that havent been excluded from the DHCP scope.

 

 

Use to be a big massive mess before I joined the school, never use to know any of the IP addresses for anything!

 

Hope that helps

 

 

EDIT - DAMN other people beat me to it!!!

Edited February 26, 2012 by pritchardavid

[pete]

As others have indicated, you differentiate so IPs make sense from a network management perspective.

 

We also differentiate on the 3rd octet so we can look at an IP and know what sort of device is using it.

 

Oh, and write down your static assignments in a Wiki or similar, or your co-workers may hunt you down with sticks.

[Oaktech]

Oh, and write down your static assignments in a Wiki or similar, or your co-workers may hunt you down with sticks.

 

Yes, yes we will. and flaming torches and pitchforks.

 

Also, impress on your co-workers that they should check both the dhcp reservation list and the documentation on static ip's to ensure they don't plonk the new printer on the same IP as the staff room copier...

[glennda]

We have the following IP's and Vlans - The Scope is huge per VLAN (but it works dhcp limits the amount of addresses given). We have used the following rules when setting up Vlans.

 

10.VlanNO.0.X - DHCP runs from 10.VLanno.1.x through to 10.VlanNO.4.255, with a Subnet of 255.255.0.0 Gateway being 10.VlanNO.0.1 (being the Core Switch). We use 10.VlanNo.0.x for Statics on that Vlan.

 

i.e Vlan 1 is 10.1.0.x, Vlan 2 10.2.0.x etc

 

Vlan1 - A block 10.1.x

Vlan2 - B Block 10.2.x

Vlan3 - Management 10.100.x (switch Management)

Vlan4 - C Block 10.4.x

Vlan5 - G Block 10.5.x

Vlan6 - L Block 10.6.x

Vlan7 - T Block 10.7.x

Vlan8 - Wireless 10.8.x

Vlan9 - Printers 10.9.x

VLan10 - Network Support (allows RDP SSH to Servers VLan blocked from others)

Vlan11 - Servers Vlan 10.11.x

[CyberNerd]

Our topology:

 

http://www.edugeek.net/attachments/forums/networks/9523d1298121236-setting-up-vlans-network-topology.pdf

[36Degrees]

Also, impress on your co-workers that they should check both the dhcp reservation list and the documentation on static ip's to ensure they don't plonk the new printer on the same IP as the staff room copier...

 

Or assign a static IP to a UPS that is in the middle of the DHCP scope...

[sted]

Yes, yes we will. and flaming torches and pitchforks.

 

Also, impress on your co-workers that they should check both the dhcp reservation list and the documentation on static ip's to ensure they don't plonk the new printer on the same IP as the staff room copier...

 

i always shove the statics in dhcp as reservations anyway makes it a simple place to look things up

[GrumbleDook]

In EMBC land there is the Standard Network Build documentation which has suggestions about how you can set up your IP range and also your VLANs.

[bondbill2k2]

Had a nightmare when starting here that we had 80 laptops with static IPs and around 70% of those were in the DHCP scope along with a server and a few printers, extended the static scope by around .50 now and add on that but we dont have much of a pattern other then DCs first few IPs, then printers and stuff added more recently just gets added onto the next free IP in that range.

 

The most annoying was a staff member who is only in once or twice per week had a phone with no client ID that had been configured to the same static as a printer which confused us why it sometimes worked and other days didn't. Most of our IP lists were out of date too, is it good practice to add static IPs to the reserve list on youre DHCP? Would allow an easy way to find them

[cbcouk]

I thought I would add my 2 pence worth...

 

We've got 2 buildings seperated via 172.17.x.x and 172.18.x.x

 

From this we have 2 cabs per floor (5 floors) so 10 cabs in all. Each cab has at least 2 VLANS, one for staff and one for students. Then we have VLANS for printers and projectors and phones with another VLAN per building for apple macs. In the server room we have a different VLAN for servers and netapp. We have around 200 VLANS but works really well as we know where everything is.

 

A bit complicated if you have just one cab or only a few hundred pcs but its great for content filtering and access control!

[synaesthesia]

I quite like our setup (put in place long before my time) - 192.168.x.x for switches and printers. Keeps non-admins off of them 10.x.x.x as allocated by our LEA (historically, no need to keep it there now but no reason to change it) for domain devices (workstations, servers etc).

 

Currently it's all flat on one network but we're about to split the subnets - so to say if we have 10.1.2.1 to 10.1.5.254, one site will be 10.1.2.1 - 10.1.3.254 (with 50 addresses put aside for servers and services) and 10.1.4.1 to 10.1.5.254 for the other, with a few more addresses aside for servers and services. Looks a little more complicated but with two sites it means SCCM and AD work beautifully to avoid traffic over the link

 

Go with whatever makes life that little bit easier for you, if you've a large number of devices then certainly look at segregation/subnets otherwise feel free to play around

[ADMaster]

Our network was just redesigned by a contractor when the new building was added, and I like the setup.

Every data closet has it’s own vlan for data, and each building has its separate vlan for various services.

For the data vlans the first 25 addresses are not in dhcp scope and used as ip reservations of printers.

So it looks something like this

Vlan 1 10.0.1.0 Data for ES ER1

Vlan 2 10.0.2.0 Data for ES TR2

Vlan 3 10.0.3.0 ES video

Vlan 4 10.0.4.0 HS Data

Vlan 5 10.0.5.0 HS Video

Etc etc

Some vlans are district wide such as

Vlan 10 Phone

Vlan 11 switches

Vlan 12 some severs / some admins a left over from new network plan, didn’t want to change critical servers if we didn’t have to.

Vlan 13 new server vlan

Vlan 14 guest WIFI

Vlan 15 Staff wifi

Vlan 16 student wifi

 

It is nice to be able to glance at an IP and know in what building it is in what data closet or whether it is staff student or guest wifi.

 

Make a plan that works for you and your situation, if you can glance at an IP and know where or what it is you have a good plan.

I try to keep a wiki updated with static assignments but also use DHCP reservations for printers and copiers etc.