Why does DHCP work this way?

[RebateMonger]

There's something about DHCP networks that I don't understand and I'm hoping someone can explain the behavior that I see.

Today I turned off the DHCP Server in a SOHO router and turned on DHCP on a new Windows 2003 Server. Both the DHCP Servers were on the same subnet and both had the same IP scope.

I THOUGHT that the PCs on the network, set to get their IP addresses via DHCP, would continue to network normally until their existing DHCP leases ran out.

Instead, all the PCs seemed to lose network connectivity and required immediate "IPCONFIG / RELEASE" and "IPCONFIG / RENEW" commands to get functional IP addresses.

I've seen this behavior before and I'm afraid I don't understand it. What am I missing?

Thanks!
RebateMonger

 

[dphantom]

Well, this is how it should work.

"Once the lease is obtained at one half the lease period the client will try to renew the lease with the original DHCP server and will continue until the lease term is seven eights complete. At 7/8th completion, the client will attempt the renew process with any DHCP server."

Gateway change? Any settings in server scope that were different from SOHO?

 

[spidey07]

That should not happen. You've got some kind of dynamic name registration problem.

 

[RebateMonger]

Well, it wasn't a Gateway problem. The PCs lost connections to each other on the same subnet. They also lost Internet connectivity. That's the first complaint that came up.

The Default Gateway setting stayed the same. In both cases, it was the SOHO router. I DID change the DNS settings. The new DNS Server was the Server 2003 box

I turned off the Router's DHCP Server and then turned on the Server 2003's DHCP and DNS servers. I figured I'd have a little while to run around the office and reset each PC's networking settings. Then folks started running to me telling me they'd lost their Internet connection and also that their client/server line-of-business software couldn't connect to their current Windows 2000 Professional "Server".

Maybe it's was DNS issue? (Like almost every other networking issue in this world.) :laugh:

Thanks for your input, guys.