Immediate DHCP release for an entire subnet?

[etonwick]

Does anyone know of an effective method of forcing all W2K clients on a single subnet to release and renew their DHCP-assigned ip address and config (i.e. without getting the users to type the command)?

We have considered using Group policy to run a script on all PC's, but this might take anywhere from 90 to 120 minutes to be applied to all.

Our reason for wanting to do this is to deal with a DHCP server failure where we may need to bring up another DHCP server that has no knowledge of the ip addresses already leased by the failed server.

Any replies or advice would be gratefully received.

 

[Cryptospy]

Why not just run a scheduled task that runs once per hour.

ipconfig /renew

Cryptospy

 

[TheLad]

If you released and renewed every hour, would that not cause problems for the person using the achine? I mean, if they had something running at the time and the release and renew happened, would this not stuff it up for them?

 

[Pistol34]

Your clients get an IP from DHCP. The DHCP server starts on fire and is no longer available. All currently logged on machines still have valid IP's. It should only take a couple of minutes to start DHCP services on a different box. When a new client come on it will broadcast and the new server will respond. The new server will have a different range of IP's. If you don't have enough IP's to spilt the subnet for 2 different pools then you could expand your subnet. The pools don't have to be equal in size there just has to be enough ip's to support new connections in the second pool.

OR

If you are lucky you can get machines to retain the last valid IP configuration it recieved before the DHCP caught fire. If you leases are long enough it will give you time to call the fire department.

OR

You could write a script that pulls all the computer accounts from AD or other source and forces them to renew. The script could excecute on a server and send the command to each box. A couple hundred machines could be released in 5 minutes. A couple thousand, well lets just hope you only have a couple hundred.

OR

Your going to reak havoc on network applications. With the script. You could use the PA to get everyone to close applications, but why not just have them reboot.

PP