Losing connection to Exchange

[cygnusman]

Hi All,
No doubt this thread belongs on the NT4 server forum but I need all the help I can get!

Since installing a new Dell 350 server to run Exchange Server our clients randomly lose their connection to the server. At these times you cannot ping the server but it can ping out to the lan. Connections from the server to the internet thru the network are OK. The connection 'returns' after 10 minutes or so! Microsoft thought this was a master browser problem and have studied our network config and they declared it OK but nevertheless problems persists!

Moved the hard-disk and functions to a second identical server and the problem moved!

I suspect problems with Dell 350 design.

Any ideas or anyone seen similar??

Many thanks,

Cygnusman

 

[ElijahBaley]

Bit of a long shot, but I wonder if you are experiencing broadcast storms in the Exchange collision domain - could be caused by a faulty NIC spewing frames out onto the network or poor LAN design.

What is your Hub switch setup?

EB

 

[cygnusman]

Dear EB,

Thanks for reply.

The server connects direct to a 16 way rack hub then on to the LAN where connections spread across 4 other small hubs. There's only 16 machines altogether on network in small office. All cabling CAT5.

No remote sites or RAS connections. Exchange server connects thru router to adsl.

Have tried alternate NIC. Problems occur even if Exchange services all stopped!

Regards.

 

[N0ktar]

It couldn't be a faulty NIC, since the problem occurred on two different servers.
Reinstall TCP/IP protocol stack, reapply SP4 for Exchange and SP6a for NT.

 

[cygnusman]

NOktar,

Thanks but all that has been done several times with no results!

Cygnusman

 

[ElijahBaley]

Hi

I dont want to lead you too far astray but I would definetly take a look at all of those hubs, you can ping out to the Internet from the Exvhange server because you are directly connected to the router right?

Your Exchange server looses connectivity to the clients from time to time.. could be one of those hubs locking up, they do that if they overheat (make sure they are well ventilated).

Could be well wide of the mark, but thats what I would take a look at!!

Regards

EB

 

[cygnusman]

EB,

Thanks again. No the server is connected to the router thru the hubs like the rest of the network. Everything is connected eventually to a PIX then out thru the router!

Regards,

CygnusMan