[Enigma IE]

Originally Posted by joe2687

Server B is up and functioning. Ripped down the DNS and re-installed. For sh*ts and giggles, I enabled the 2nd onboard network card and switched to that one, everything working fine... Still have an IP address conflict, but would an conflict between 2 client machines show up at login on the server??

It two clients have duplicate IPs, it may show up in the EventViewer in the domain controller, not at the server console. If your getting a conflict message at the server console, this tells me another device has same IP address as your server, in that case, you will still need to track down the rogue machine somehow.

[joe2687]

Originally Posted by Enigma IE

If your getting a conflict message at the server console, this tells me another device has same IP address as your server, in that case, you will still need to track down the rogue machine somehow.

That's what I was thinking... It's just finding it now!! Lots of people come here with laptops (I work in a college) so I'm thinking maybe somebody got a laptop for xmas, and had it set up in their home with a static IP and it's the same as our server...

Might be a plan to move the IP range onto something a little more exclusive, like 192.168.155.x, less chance of complications like this. I was very surprised the server came back up to be honest when I switched the network card, I thought if a network card was bust then it wouldn't allow any ping/comms through it.. One to remember!

[Static M.e.]

You could always change the IP address of the server to a high number like x.245 the chances of someone having that number would be a lot slimmer than x.1 or .2 etc

Doesnt solve the problem but it might be a work around

[IrishB.ie]

Originally Posted by joe2687

I have went around 200 machines, and all laptops, and none have a static IP. This is bugging me indeed.

Check the address pool on the DHCP server. Also whatever IP you use on your servers, make sure they are excluded from the DHCP scope.

[joe2687]

I went through the address pool on the DHCP server before I went around the machines, eliminated a few by that, unfortunately the was no proper naming convention for PC's before I came here, so a lot of them are defaults (ADMIN-PC) etc..

Originally Posted by IrishB.ie

Also whatever IP you use on your servers, make sure they are excluded from the DHCP scope.

Scope is from .25 - .254, excluding .100 for server A, I suppose changing the IP address to something high and adding an exclusion in the scope would eliminate the duplicate IP problem, would be less work than changing the whole range, but things are kind of messy here to be honest, maybe I should look at this as an opportunity to wipe the slate and do it my way..

Thanks for the input today everyone, much appreciated.

[Jumpy]

192.168 is not good to use in an office environment.

You are always recommended to use a range in 172.16.0.0/12 or 10.0.0.0/8 (if you are that large)

The firs will give you over 1 million addresses. It will also not conflict with anyone plugging a default POS home router into your network.

Most standard home routers will give out 192.168 addresses.

[joe2687]

Yeah I generally use the 10. range.. I've inherited this network, and the setup is a little outdated. I plan to upgrade to 2008 once I get everything working OK. I hear it's a bumpy ride though...

[Static M.e.]

I never really upgrade servers just move the services to new machines. I find it helps to keep things under control because you know exactly how you built the new machines and what you had to do to get that service running. We also run new servers in parallel with the old ones to make sure we dont lose anything.

On the ip range, I would agree use this time to change the DHCP range to 172.16.0.0/12 or 10.0.0.0/8.

If you send out an email today for everyone to switch off their pc at the weekend. Then you can make the changes Friday evening\Saturday and once staff reboot on monday they will pick up the new range without any fuss.

If you only have two servers I would do it in a heartbeat. You should also give your self more IP's to play with. Set your range 10.0.1.20 to 10.0.1.240. I like to have a couple of statics for Printers, Servers, testing etc.

[joe2687]

Originally Posted by Static M.e.

I never really upgrade servers just move the services to new machines. I find it helps to keep things under control because you know exactly how you built the new machines and what you had to do to get that service running. We also run new servers in parallel with the old ones to make sure we dont lose anything.

That's a very good point, I have a spare blade server here, I might load 2008 on that and transfer some of the roles gradually, starting with DHCP. Seems like a bit of a waste running 2008 on a non Hyper-V server, but it would do for a start. I also have ABTutor console running on the server, so I can do a shutdown accross the board to eliminate any issues with running machines getting a new IP.

I currently have the scope going from .25 - .254, with all printers, WAPS, etc coming in under the scope.

[Static M.e.]

Give yourself some space at the end of the scope too, you never know when you will need extra IPs...

For instance we recently changed Internet providor so we had to have the two connections running at once. We used .254 as the new gateway for testing, .250 for the old gateway and the router inbetween was .252...

Having our default gateway at .250 works very well for us. Dont forget that once you get the scope up and running you cant edit the scope to make a change you have to build it again from scratch which is a pain in the ass if you have a lot of reservations or VoIP phones.