Last Thursday morning, the first computer on my Windows Server 2000
network restarted would not reconnect to the network.  I tried
everything but the computer just would not receive an automatic IP
address from the server.  The only thing that worked was to assign it
a static IP address - then it connected fine.  Then, one-by-one, every
single one of the remaining computers (10) on the network would not
reconnect after being restarted.  They all had the same problem with
receiving an IP address from the DHCP server.  However, when I
assigned each of them a static IP they connect fine.  Since this
happened to each computer with different operating systems and
hardware, I assume the problem is related to the server and its DHCP
server.  Was there recently a virus or hack released that could have
caused this (ran virus scan with no results)?  Coincidentally, a
couple of my workstations are laptops that can connect and receive an
automatice IP address from other networks (ie home, hotel, etc), which
further strengthens my belief that it must be my server and not the
workstation's software, hardware or configuarations.  Any suggestions?

yes, check the DHCP server service (is it started). Also make certain
you don't have another DHCP server on your network. (Someone didn't
plug in a linksys router somewhere, did they?)

Check to see what IP address one gets if not the one you want.
IPCONFIG /all should tell you where the IP address came from.

Well, it looks like the the DHCP server may not have been running (may
have expired or something) on the server.  So I activated it and Bingo
- I'm connected to our network.  But for some reason I cannot connect
to the internet.  I can ping succesfully within our network but not
the router or anything outside.  The computers that are still
configured manually with a static IP still connect to network and
internet.  Sort of solved one problem and created another!

That was the answer afterall.  I went back into the server DHCP
settings and had to configure a couple more items (scopes, router,
DNS, etc) and everything works now.  Submit your comment as an answer
and we'll be done.

Thanks Crythias-ga!

The computer eventually stiooed working because the DHCP service has
stopped working on the Windows 2000 server.... They all "lease" an IP
address for a certain amount of time... normally 1 week.

All Machines will normally will attempt to "re-lease" the same IP
after a certain amount of time. ie- 50% of the lease is complete...
After 100% of the lease, the computers would no longer be able to use
the address...

Also any laptops (or computers that were ahut down) would have the issue on bootup.

Thomas Poole

Only Researchers (with hyperlinked usernames) can post answers. From
me is free comment.
PS: if you have DNS... your DHCP DNS servers should point to the
Active Directory DNS server, not the Internet DNS server. Your
Internal (AD) DNS server should then forward all Internet requests to
the Internet. This will make things a lot easier on you and stop some
errors and problems connecting to your network.

The real line commande is :
ipconfig /release > to release the IP adress to DHCP Server
ipconfig /renew > to get a news IP adress form DHCP Server

erz-ga, that's correct, except it won't work if the DHCP server isn't
running (as is/was the case here).

If your network meets the following 2 conditions:
1) An Active Directory environment
2) More then one domain controller for this domain, and this
server(your DHCP server) is not a global catalog server.

If the link has died between your DHCP and your global catalog server,
it seems to sometimes lose its "authorization" to hand out IP's with
DHCP.   This link has to go down for awhile for this to happen.

So when you stopped the DHCP service, and restarted it, it probably
re-authorized the server to hand out leases again.

To fix this problem in the future, just make both servers are Global catalog.