I've installed all features of dhcp redundancy. That's work fine on both server.

The problem is on my desktop dhcp client: when I'm adding any new dhcp server (the one on windows server 2003 or the one on the firewall), and that the main primary dhcp server is disabled, the clients can't get a new ip adress.

I found that I have to disable the ethernet card (using disable on the "local area connection" in the "network connections"), and then I have to enable it.

It looks like there is a cache when you renew the ip adress with "ipconfig /renew".

The problem: I don't want go on each desktop to disable and enable again when the first dhcp server crash.

Has somebody any idea about my problem?

Thank you!

p.s.: even when I restart the computer, it doesn't find the new dhcp server. That's the same problem than "ipconfig /renew".

I found a solution without the need to disable the ethernet card.

I have to release the ip address first, and then catch a new one with the dhcp:

1) ipconfig /release
2) ipconfig /renew

Then, it's working. Now, my goal is that each desktop, when they restart, catch an address from the second server, without me typing ipconfig and so on.

Thank you for your idea and help.

Does the computers keep the same address or does it not get any address at all?

What about just putting a BATch on the users desktop, that just does that release and renew. Not really a beautiful solution, bur sometimes the easy things are the best things in life :-)