Computers won't retain DHCP address

[TheGrandHooHa]

Recently, computers have had trouble getting and retaining IP addresses via DHCP. A computer will have the correct IP address, but after restarting/shutting down, it will come back up with an IP address in the 10.0.0.x range (needs to be 172.24.5.x). To get the computers to get the right IP, I have to release, flushdns, and renew. This gets me the right IP, but then if I restart again, it loses the IP and goes back to 10.0.0.x. This is a major problem; computers in the 10.x range cannot access any of our servers - the 172.24 IP is essential.

There have been no changes in configuration here- this is completely out of the blue. The affected computers are running Win2k and WinXP. They connect to the DHCP server through different switches, so I don't think it is a result of a switch or other piece of hardware going bad.

Would Winsockfix do any good here? I wouldn't think so; nothing appears to be corrupted; this may well be a problem with our network.

Let me know if you need more info; my boss has charged me with fixing this, but I am not a master of networking and I know even less about our switches (Cisco 2950) and how to configure them, but I will try to get whatever info you folks need.

Thanks in advance!

-Chris

 

[bcastner]

As guesses only:

1. Someone has added a DHCP server to the network. One common source: someone with a notebook has brought in a wireless AP or wireless router without disabling DHCP.

2. WinsockFix will not hurt anything, and is OS sensitive. It responds differently depending on the OS version in use.

But, I suspect it is not called for in this instance. My argument in #1 is more likely the case. If you were pulling APIA or 0.0.0.0 addresses, the WinsockFix utility would be the first thing I would use. See the discussion faq779-4625

 

[compuveg]

bcastner's right, there's got to be a new DHCP server somewhere. Find them and read them the riot act. Plugging something has got to be against company policy, and in some companies could be grounds for termination.

 

[bcastner]

Some other things are possible, see:

http://support.microsoft.com/default.aspx?scid=kb;en-us;167014

But the 10.10.x.x adressing is too suspicious. There has to be a second DHCP server added somewhere. One possible route to find it:

http://support.microsoft.com/?kbid=303351