Users disconnected after 7 hours

[dschrag]

Running SBS 4.5, 10 users. Clients are mostly Win98, one W2K. Users are spontaneously losing their connection to the network. This has been happening since before I started working with this network, many months ago.

-- This happens to some but not all users. For those affected, it happens every day.
-- It always seems to happen 7 hours after login. Don't know if it's exactly 7 hours every time or just roughly that amount of time.
-- Have checked DHCP settings (leases are infinite) and logon hours in user manager (no restrictions).
-- Have enabled auditing of all failure events in user manager audit policy. Nothing extraordinary in security event log.
-- No unusual activity in system log or application log, either.
-- Users are able to solve the problem (temporarily) by rebooting.

I don't know what other settings or logs to check, or even what keywords to use to describe this problem in a knowledgebase search. Any help would be appreciated.

 

[Cerati]

Are there any differences betwen the machines the users who do get kicked off use, and the ones that don't get kicked off use ?

Are there any differences in how they connect to the network ?

When you say they lose their connection to the network, do you mean the "network" as a whole or 'just' the NT server ?

That it happens after a certain amount of time would suggest a resources problem - it could be either end. Have you checked with performance monitor that your server is adequate for what you expect of it ? Have you had any licensing warnings ?

When the clients crash do the machines themselves fall over ?

 

[dschrag]

I have not been able to identify any meaningful differences between affected and unaffected clients, partly because I don't really know what to look for. Obviously there are SOME differences -- it is a very heterogeneous hardware environment, user names are different, etc. The Windows 2000 clients do not seem to have the problem, but there are some Win98 clients that are also unaffected.

Not sure what you mean by differences in how they connect to the network. They are all connected to the same Fast Ethernet switch, all using TCP/IP. Are there specific network properties I should be concentrating on?

In an SBS environment, losing connection to the NT server is losing connection to the network as a whole. I suppose one thing I could try is having users attempt to ping their peers in addition to the server when they lose the connection. (I'm rarely on site there.)

I have not had any licensing warnings, although the license service works a little differently in SBS -- you can't access it directly. I did discover a discrepancy in the number of licenses that were in the registry for NT vs. Exchange, but that has been cleared up. There are only 10 users in this network, and the server should be quite adequate.

The clients do not actually crash. There is no warning to the user that anything bad has happened until they try to print or open a file and discover that they can't. The client never locks up -- they just have to reboot it to get back into the network.

 

[Cerati]

OK....

It's fairly likely you can rule operating system out as the cause then, although with only one w2k box.....not entirely.

On the workstations - do they all use the same type of network cards ? Do you autonegotiate the speed/duplex or have you got it manually set ? Is there any difference between the network settings of those who drop off as opposed to those who don't ? Do your clients go through structured cabling to the switch or is it a spaghetti on the floor job ?

It might be interesting to see if you can get a conectivity test going.........if this tends to happen after a given period of time, at a certain(ish) time of day you might schedule in a continous ping on one of the w98 boxes that aren't so stable to see if you do lose network connectivity at the same time as the connection to the SBS server is terminated.

 

[Janezt]

Try to change idle time interval using command prompt (net config server or net config server autodisconnect:time)

 

[dschrag]

The idle/autodisconnect time is set to 15 minutes, which is the default. Obviously users are not getting disconnected after 15 minutes, though. So does it make sense to change this setting, and if so, to what? -1 means no autodisconnect ... that doesn't sound like a good thing, though.

Cerati: I will get answers to your questions soon.

 

[dschrag]

Looks like the problem was the W32.HLLW.Qaz.A virus, which had somehow escaped detection on some of the PCs. The problem seems to have disappeared now that the PCs have been disinfected.

Thanks for your suggestions, though ....