IP address conflicts

[Bern2002]

We are running netware 5.5, pretty plain vanilla. All workstations log into the same server. We are using dynamic addressing. Some workstations are win95, win98, win2k.

If a person is out of the office (does not log on to the network for a day or more), the next time they log in, they get an address conflict, and we have to go to the dhcp server, remove their address, and assign a static ip adress at their desktop. There is no error message at the dhcp server, everything looks good.

At the end of the week, we usually go back and remove the static addresses, and re-configure the offending workstations to dynamic addressing and it's o.k.

This mainly appears to be happening only on the win95/98 workstations, not the win2k workstations.

Why would this happen?

 

[TheLad]

Firstly, NetWare 5.5 does not exist. You are either using NetWare 5.0 or NetWare 5.1. Have you applied any Service Packs?

Secondly, are your Win95 clients using Winsock2? The download can be found at:

http://www.microsoft.com/windows95/downloads/contents/wuadmintools/s_wunetworkingtools/w95sockets2/

Not too sure why Win98 would do this (the above does not apply to Win98). What lease time have you got set? -----------------------------------------------------
"It's true, its damn true!"
-----------------------------------------------------

 

[rjs]

There seems to be a big difference with whether you actually power down the workstation or just log off. I've found if you power down the PC (not restart, reset, etc), it will pick up a new address if its existing lease has not expired yet and its existing IP address has been given out by NetWare DHCP server.

 

[mtbiker]

Try using "winipcfg" from the DOS prompt. This will bring up the IP settings for the workstation. Verify the information such as the DHCP server and DNS. Also check the default gateway.

If you expand the menu, at the bottom you will see a release button and a renew button. Try releasing the IP and renewing. I would be interested to hear the results.

Lastly, check to make sure their are no workstation policies out thier hanging up your workstation.

Bill Shaw, CNE

 

[TheBoySmith]

On the DHCP server set the lease time to a high figure like 60 days. This will allow the address to re-new after 30 days. Hopefully most people will be in the office once a month.

Lee Smith
Associated Network Services
Snr Systems Engineer
Lee.Smith@ANSPLC.Com

 

[Bern2002]

Sorry for the type-o, we are running 5.1. Anyway, RJS, when this conflict occurs, we do completely shut down the workstation and re-boot, yet the workstation continues to be assigned the same conflicting address.

mtbiker, I do run winipcfg, but I do not usually renew. I just release and then manually assign a static address. Next time I'll just renew and see what I get. If this works, I'll still have the initial problem whenever someone is out of the office and skips a day or more of logging in.

TheBoySmith, that's a good idea. If it works it would solve everything. Currently I believe we have the lease expiration set to 7 days.

Thanks for all of the great ideas.

 

[TheBoySmith]

There is a known issue with 95/98 and dhcp servers that aren't microsoft. The client does not release the address on shutdown thus you can get conflicts if the machine has been off for a period of time and the dhcp server has re-leased the address. There is not a proper fix but you can run a batch file in the registry, runservice. The batch file will run a release then renew. There is also a tid on novell that has a reg hack that forces the workstation to release the address on shutdown. Lee Smith
Associated Network Services
Snr Systems Engineer
Lee.Smith@ANSPLC.Com

 

[dan]

Two suggestions:
In the DHCP manager, double click on the server in the lower right corner.
Select the options tab.
Check the "Ping enabled" box.
This will ping an IP address before assigning it and choose another if something answers.
Also, run a full DS repair on all servers containing a replica. Since DHCP is handled through DNS, an corruption in your DNS can cause duplicate IP addresses.
We had this problem in the past. These two items have virutually solved the problem.
Dan

 

[TheLad]

I think Dan means NDS not DNS. -----------------------------------------------------
"It's true, its damn true!"
-----------------------------------------------------

 

[ab2002]

Hi

Do you run dhcp on your netware server? If so you can set the rate your dchp lease will expire.

cheers

Ab