DHCP Not giving proper IP addresses

[pharback]

Two week ago, I have been having users come to me to tell me that they could not get on the internet. I would go into the user's computer and the IP Address is not the correct address that the DHCP is suppose to give out. Then I would do a ipconfig /release and then a /renew. That worked for a while, but each time the computer gets turned off, the computer would be reassigned a new wrong address. Plus, during this time, the Default gateway is not being assigned to the computer either.

Now a week ago, I try to do a ipconfig /release, /renew, and it would not get the new address. I would have to go into the network neighborhood and assign it a static ip address, let it configure, then I would select the obtain a IP address. This is when the computer would be given the proper address from the DHCP.

This has been going on, and I do not know how to fix it.

This all started when I put updates on my servers, I removed the updates, but the problem continues to happen.

If there is anybody out there that could advise me, I would appreciate it.

Thanks
Pharback

 

[Saugilsr]

Can you give some more details on your network?
How many DHCP servers do you have? Scopes?
What did the incorrect IP's look like? Is it the Auto asigned addr?
When they get the wrong IP where does ipconfig /all say the DHCP server is?

 

[pharback]

I have 2 server giving out IP addresses. The primary server is x.x.1.11, and the secondary is x.x.1.10. The scope for the 1.11 is x.x.1.100 to x.x.1.149 and the scope for x.x.1.10 is x.x.1.150 to x.x.1.199.

The incorrect address is in the lower numbers that are not already given out with static IP addresses, like x.x.1.2 and up.

What is Auto Assigned address?

The ipconfig /all looks like:
IP Addr..........x.x.1.15
SubnetMask.......255.255.255.0
Default Gateway..
DHCP Servers.....x.x.1.11
Dns servers......x.x.1.11

Primary WINS.....
Secondary WINS...

It’s supposed to be:
IP Addr........… Between x.x.1.150 and x.x.1.199
SubnetMask.......255.255.255.0
Default Gateway..x.x.1.1
DHCP Servers.....x.x.1.11
Dns servers......x.x.1.11
x.x.1.10
Primary WINS.....x.x.1.11
Secondary WINS...x.x.1.10

I just completely shutdown a computer and then restarted it. The computer's ipconfig /all showed an IP Address of x.x.1.4,

If there is anything else you need, please let me know.

Thanks
Pharback

 

[Saugilsr]

Huh. Interesting. OK, when the computer gets a IP in the wrong range does the lease show up in the DHCP mmc?

Is it the same computers all the time?

If you stop the DHCP service on the .11 server does the problem still occur?

Id almost be inclinded to delete the scopes. Remake them and restart the DHCP service. Just to rule some things out.

What updates were they btw? On what type server 2k3?

 

[m3the01]

I would have said this is a rogue dhcp server but sense there issuing in the correct X.X range then i would have to say this is a configuration issue.

check and have someone else check the configuration of the two dhcp servers. Its easy to miss the some thing stupid. Its the best to have someone take a quick peak.

Good luck,

If anymore information comes to light please share.

 

[pharback]

Saugilsr:
Huh. Interesting. OK, when the computer gets a IP in the wrong range does the lease show up in the DHCP mmc?
No the IP address never showed up, but I noticed that there were Bad Addresses showing up in the MMC, But the address does not show up as x.x.x.2 or the lower numbers, the show up within the range.

Is it the same computers all the time?
No, it continues to happen with computers that get shut down, adn then restarted.

If you stop the DHCP service on the .11 server does the problem still occur?
Yes, I shut down both x.11, adn x.10 before I started this question.

Id almost be inclinded to delete the scopes. Remake them and restart the DHCP service. Just to rule some things out.
Should I do this while everybody is on the network, or should I do this when people are off the network.

What updates were they btw? On what type server 2k3?
The updates are KB842773, KB890859 - KB894320 (5 total)
The servers are Windows Server 2000.

This might be more info you might need to understand. 2 to 3 weeks prior to this problem, I added a new router with T-1 capabilities from a DSL line.

Question: Could router take the role of DHCP.

Another issue, I came in this morning to check the MMC on both servers x.x.1.11, and x.x.1.10, and both have 3 computer registered that have IP addresses, and I have check through out the office, and a few computers are showing the right ipconfig /all configuration.

Any Ideas.
___________________________________________________________

m3the01 (TechnicalUser) 26 May 05 16:28

I would have said this is a rogue dhcp server but sense
there issuing in the correct X.X range then i would have to say this is a configuration issue.

check and have someone else check the configuration of the two dhcp servers. Its easy to miss the some thing stupid. Its the best to have someone take a quick peak.

Good luck,

If anymore information comes to light please share.

This server has been running for a year plus, I added the updates and then restarted the servers so the updates would take, then the following Monday, the DHCP started to act up.

Thanks
Pharback

 

[Saugilsr]

Ok. I think we need to step through this:

After hours STOP (not restart) the dhcp service on both servers.

Restart a client computer. Release/Renew. If it get an IP you have a rogue DHCP server someplace.

Start the DHCP service on ONE server. Restart the client computer. See if it checks out ok.

Stop the service and start it on the OTHER server. Restart the client machine and see what happens.

I guess you could do this mid afternoon once everyone has a lease and doesnt need to reboot their machine. But I find murphys law kicks in with users around.

Hopefully you can isolate the problem that way. If you isolate it to server machine delete the scope uninstal/reinstall the dhcp service. Rebuild the scope.

I don't think the router is involved because dhcp requests aren't forwared unless you configure the router to do so.

 

[pharback]

Thanks, I'll try it this weekend, eventhough it's a holyday.