WIN98 and subnet mask issues

[INArtCtr]

Hope this is the right forum to post this in -- we have a LAN with a mixture of 98 and 2000 workstations, connection to an NT4.0 domain server. We use dynamic IP addresses. Suddenly last Thursday night, we started getting IP conflict errors and having issues browsing the web. I have determined that all of the 98 stations are getting a subnet mask of 255.255.0.0, instead of 255.255.255.0. Settings on the server are correct, the 2000 machines are getting the correct subnet, and everyone is connecting to the domain and Exchange without problem. Doing an ipconfig release and renew solves the problem until people reboot, then they lose the subnet all over again. We have made no changes to anyone's software or hardware recently.

I have heard that this may be a switching issue -- we use Cisco routers and switches. There are just so many directions I could take the troubleshooting - 98, NT, the switches, DHCP, even a possible virus -- I'm just not sure what to do next. Any thoughts?

 

[TekTippy4U]

Maybe this utility can help you sort it out;

http://www.microsoft.com/windowsxp/expertzone/tips/april/cerelli1.asp

TT4U

Notification:
These are just "my" thoughts....and should be carefully measured against other opinions.
Backup All Important Data/Docs..All involved shall be spared the grief.

 

[TekTippy4U]

more possibilities;

http://support.microsoft.com/default.aspx?scid=kb;en-us;138238

http://support.microsoft.com/default.aspx?scid=kb;en-us;255999

http://support.microsoft.com/default.aspx?scid=kb;en-us;258453

TT4U

Notification:
These are just "my" thoughts....and should be carefully measured against other opinions.
Backup All Important Data/Docs..All involved shall be spared the grief.

 

[INArtCtr]

Tek,

Thanks for the ideas -- I will check them out. Two questions -- does the first utility work for 98, as well, and since we don't have RAS installed on out network, does the second one still apply? Thanks!

 

[TekTippy4U]

I believe the first one would get installed on the WIn2K Server...to parse the 98 machines, to get all Ipconfig info in a GUI interface rather than using a command prompt...

The RAS thing wouldn't apply i guess...just threw out some possibilities is all..

TT4U

Notification:
These are just "my" thoughts....and should be carefully measured against other opinions.
Backup All Important Data/Docs..All involved shall be spared the grief.

 

[mattjurado]

Suddenly last Thursday night, we started getting IP conflict errors"

What were the errors, how many machines involved? You say ip conflict, but this typically means 2 computers have the same address.

You renew the addresses and then its okay until a reboot. Then you get a different mask?

This doesn't sound like a switch, or even a virus (although it could be a virus, just doesn't sound like one). I would look at the dhcp database on the nt server corrupted.

Or, have you added any new devices to the network, perhaps a new router that might have dhcp turned on?



Matt J.

Please always take the time to backup any and all data before performing any actions suggested for ANY problem, regardless of how minor a change it might seem. Also test the backup to make sure it is intact.

 

[mattjurado]

Might look at this...

http://support.microsoft.com/defaul...port/kb/articles/q145/8/81.asp&NoWebContent=1

Database might need compacting. You might also create a new one, although you might wait until you really have to create a new one.

http://support.microsoft.com/?kbid=173396

Matt J.

Please always take the time to backup any and all data before performing any actions suggested for ANY problem, regardless of how minor a change it might seem. Also test the backup to make sure it is intact.

 

[INArtCtr]

Matt,

I would say of the 23 WIn 98 machines on the network, about 5 have gotten the IP conflict message -- very intermittently. The XP and 2000 machines are receiving the correct settings and have no IP or mask problems.

Once I do a release/renew, the mask is correct, but when they reboot it goes back to the incorrect setting.

Nothing new has been added to the network in months, so the mystery is all the deeper.

Thanks for the links -- we will check into the database.

 

[INArtCtr]

Just giving a little bit of resoution to this issue -- we checked out the database size and it was well within the limits -- everything else checked out, as well. We ended up giving all the workstations static IP addresses, which has solved that part of the problem, although we still don't know what caused it. Since we are upgrading to XP and Server 2003 later this year, we will leave it that way and hope the upgrade keeps this from happening again....Thanks to everyone for their help.

 

[mattjurado]

Its funny, people always criticize me when I advise to assign static IPs. DHCP just always adds that extra question mark to the equation...

Glad it worked out for you.

Matt J.

Please always take the time to backup any and all data before performing any actions suggested for ANY problem, regardless of how minor a change it might seem. Also test the backup to make sure it is intact.