New IP addresses, New scope needed - I don't have a clue

[stu1892]

Hi,

 

I've been charged with the responsibility of adding new IP addresses to the network and i don't have a clue. I'm currently viewing DHCP on the domain controller, staring at 'New Scope' on the current server.

 

The local authority have given us 2 new ranges (obviously these aren't the real ones )

100.100.10.1 - 100.100.13.254

and

100.100.14.1 - 100.100.17.254.

 

We already have an existing range in DHCP.

 

I quite literally have no idea where to start. I think i done a week of this in my final at Uni!

 

Basically i need to add them to the DHCP scope but i'm a bit sceptical about going straight into it without having advice from others plus reading everything i can online.

 

Any help greatly appreciated.

 

I'm sure i've not given enough information, but i'm a bit all over the place at the moment.

 

Cheers

Stu

Edited July 28, 2009 by stu1892

[FN-GM]

Ideally your best changing your subnet mask. If you have a play with this you can decide what is best for you - Online IP Subnet Calculator

[srochford]

Are the new addresses contiguous with your old addresses? (eg you've given an example of:

100.100.10.1 - 100.100.13.254

and

100.100.14.1 - 100.100.17.254

if your old addresses were:

100.100.8.1 - 100.100.9.254

then the new ones just follow on and you can just change the subnet so that you're actually using

100.100.8.1 - 100.100.17.254 (use the subnet calculator posted to work out the subnet mask!) You should be able to extend your existing range to handle that.

 

If they're not contiguous then it's a bit more work but not impossible - look at the settings for the existing range (gateway, DNS name, DNS server etc) and make a copy of that range but using your new addresses and subnet masks.

[stu1892]

Cheers.

 

FN-GN - that's a bit above my head at the moment. I remember parts of it from uni though!

 

srochford - Sadly, they aren't continuous. The current range is;

100.180.104.0 - 100.180.106.250

 

Although i think the Scope itself is 100.180.105.10 - 106.250

 

I'll have a look into the gateways, DNS and subnet masks, as suggested.

 

It's been a long time and i'm lost already.

[stu1892]

Ah!

 

Contiguous. I misread what you typed.

I don't know to be honest, i'm guessing 100.180 would mean that it's a different subnet despite coming from the same LA?

[stu1892]

Ok, i'm just going to post the way it is as i'm lost having read quite a bit on this forum and through google. I don't know why i messed about with changed addresses.

 

Current setup:

 

IP. 10.179.144.1 - 10.179.146.254 (scope name in DHCP says 10.180.144.0)

 

Subnet Mask: 255.255.252.0

 

I've been given two new scopes by the LEA.

 

10.137.20.1 - 10.137.23.254

and

10.137.24.1 - 10.137.27.254

 

I assumed that i could just add them without a problem, but reading similar posts (by people who actually have a clue) it looks like it's going to be a nightmare for me. I haven't done anything like this in 5 years and even then i was hungover during that module most of time.

 

I don't know where to start. I have a list of devices and systems that have static IPs and my boss has told me to get those first.

 

Any help appreciated. An idea where to start would be great

[JJonas]

We are actually doing this next week.

At the moment we have two scopes set up in DHCP. There is our present one that is active and our new one that is deactivated. On our new scope under address pool we have an exclusion range set up ready for all of the things that use fixed ip's. I believe the plan for next week is to go round and assign the fixed ip's to the things that need them. Then deactivate one scope, activate the other reboot all the pc's cross fingers and hope it works. We have put the whole week aside for the job so we should have time to fix it if we break it.

[GrumbleDook]

So you have one /22 range already and you are adding in an additional 2x /22 ranges and all three are non-contiguous.

 

First, you should be a Layer 3 infrastructure and you really need to speak with your LA about how they intend to apply these addresses to the provided router. I can only really talk about how it is done with EMBC and a few other possibilities.

 

1 - your core switch becomes your router / default gateway and manages traffic between all three ranges.

2 - you have a small range that forms an 'inter-link' connection between your core switch and your router.

3 - you sacrifice chickens, goats and small children.

 

The other side is when you start using the different ranges in different VPNs and at that point you need to sit down and start planning it all from scratch, dig out your old notes, the training books and even the simulator.

 

Not a comprehensive answer but is the starting point that we point our schools towards.

[stu1892]

Thanks for the replies.

 

JJonas - That makes sense to me. Should i continue with all this and screw it up, is it as simple as activating the old scope again to sort it all out (other than changed static IPs of course)?

 

GrumbleDook - Regarding the infrastructure etc, that's definitely not my job and i'll probably pass what you've said on to my boss.

 

All i have is the information given to me from the Council's ICT Team;

IP addresses:

1. blah blah

2. blah blah.

 

That is literally it

[JJonas]

Thanks for the replies.

 

JJonas - That makes sense to me. Should i continue with all this and screw it up, is it as simple as activating the old scope again to sort it all out (other than changed static IPs of course)?

 

I think it might be as simple as that. I watched it being done a few years ago and was told that was why they left the old scope intact but everything went ok during that change so it was not needed. We are going to be changing our scope next week so if I remember I will post an update.

[stu1892]

Well... Something has came up.

 

Sorry for wasting your time reading the complicated stuff above, but now I'm not combing the old scope and the two new scopes.

 

The two new scopes will be used by themselves. Maybe just one of the two too!

 

I have been given no information about this at all which is why i've been stressing.

 

Anyway, if i was to create a new scope using only one of the new IP sets, could i just use the same settings as the current one has?

Edited July 29, 2009 by stu1892

[stu1892]

My thoughts on my new DHCP set up

 

Set new IPs to Switches and switch stacks around the building. - They don't need a reboot after the IP is changed does it?

 

Set Static IPs on Cluster , file and exchange virtual servers - Puzzled with this

Set static IPs on servers including gateway ip / new dns address

Shutdown servers except DHCP server, obviously!

Clear DNS Entries in forward lookup.

 

Activate New DHCP Scope

De-activate Old Scope - Correct order?

 

Change IP of DHCP Server

Reboot DHCP server with it's new IP.

New DNS Should only show DHCP server.

 

 

Start booting servers

Cross fingers

 

Then all the printers etc etc.

[srochford]

My thoughts on my new DHCP set up

 

Set Static IPs on Cluster , file and exchange virtual servers -

Set static IPs on servers including gateway ip / new dns address

 

Then all the printers etc etc.

 

If you have to change DHCP scope etc then I'd take the opportunity to think really hard about what has to be on fixed IP - everything that's on fixed IP means more work if the IP range ever changes again (and it will!!!)

 

If you just add reservations to your DHCP scope for anything which you want to have a fixed address then it's easy to change those reservations later (you can export the current reservations and probably do search/replace if you're doing a predictable change and reimport)

[stu1892]

Yeah, the thing is, they're all static at the moment so i'll have to change them anyway at the moment!

[srochford]

Yeah, the thing is, they're all static at the moment so i'll have to change them anyway at the moment!

 

But if they'd been DHCP last time then you'd have nothing to do this time :-)

 

You can't change the past but you can make life easier for the future and it's probably a lot less effort to tick the box saying "DHCP" then enter new IP, subnet etc etc (particularly as you probably have to do that via a series of poor web interfaces or even by visiting devices with a laptop!)

 

It might not be the right thing for you but it's just something to think about.

[stu1892]

Totally agree.

 

But if i have to do all this work, i'm not doing it next time so it's a lesson for the next person who has to do it

 

My boss is away now and i can't get into three stacks of Nortel switches. All the passwords should be the same, for every switch and they're clearly not. So half the building could be off when i'm finished.