Advice needed - problem with network at work

[The_Librarian]

We have now plugged one of the problematic PC's directly into the router (bypassing the switch) and problem still persists...

Seems that you have narrowed it down.

Now the only course of action would be to replace the router itself and see if the problem goes away.

 

[gregmcc]

Def points to the router - replace and monitor.

 

[The_Librarian]

FWIW Telkom-branded routers seems to love in giving issues. Friend of ours also have a problematic telkom router.

 

[bluepoole]

Only question I have, if it is indeed the router, then wouldn't all the PC's connected to the switch, which in turn is connected to the router, be offline? Is it possible that some PC's could be online, and others not?

 

[SauRoNZA]

Next time it happens give the PC in question Static IP information (outside your DHCP range) and see if that solves your problem.

Another option is to plug any PC that gives a problem directly into the Router.

If you do the above with two different PC's it should give you some answers.


****

In my experience D-Link, that particular unit especially is quite ****. Suspect it runs out of memory and drops it's NAT table or some such.

 

[AstroTurf]

Is DHCP enabled on the router?

 

[gregmcc]

Also open cmd window on some of the PC's and leave a ping running to the router IP as well as 8.8.8.8 and a local IP on the network.

Then when it happens again check what drops out.

 

[The_Librarian]

Only question I have, if it is indeed the router, then wouldn't all the PC's connected to the switch, which in turn is connected to the router, be offline? Is it possible that some PC's could be online, and others not?

DHCP leases are renewed regularly. Check out your router's DHCP settings and the lease renewal time.

I think what happens here is that the DHCP daemon goes wonky for some reason when DHCP lease renewal time comes up, and it doesn't respond, causing the PC's to lose their DHCP settings.

Set one or two PC's with static IP's outside the DHCP lease pool, and see if the problem persists.

Should the two PC's with the static IP's remain connected while the rest loses connectivity, then it is the DHCP daemon portion of the router giving you grief.

If the problem still persists, even with static IP's, then it's time for a new router.

 

[bluepoole]

Thank you so much for all the advice - it seems we have solved the problem.

One of the PC's is supposedly infected with a virus which, by the looks of it, causes IP address conflicts...we unplugged this PC and everything is now 100%

 

[gregmcc]

Nasty - which virus is it?