ML370 G3 @ Win2k3 Ent - Looses Network connectivity

[Dimitris Vayenas]

Something extremely weird is happening.

In all our servers we observer the following behaviour, since they were moved to a Cisco 3750 (Gigabit) switch:

Every so often then servers will loose connectivity for a few minutes. Then, suddenly, after 4-5 minutes the network will reappear. In some servers this happens once a day, in others it can happen upto 10 times a day, usually when traffic is high.

Please dont tell me that there may be a driver issue. We have the latest drivers (7.80) and this behaviour also appears in some servers that we use the Intel Pro 10/100/1000 Adapter (also with the latest drivers).

Please note that the servers run Windows 2003 Enterprise (with all updates). Also note that they belong in our DMZ (i.e. 10.1.1.2 - 10.1.1.12). There are no IP conflicts.

The issue occurs regardless of the cards set to auto or to 1Gbps/full duplex connection. The cable used is a Panduit CAT 6 shielded, 5 meters long. The cable connects to the switch directly. It is not patched.

But also please note this as well. In some cases one webserver will be able to see the database server. Another webserver will be able to be seen by the users but will be unable to communicate with the database!

I forgot to mention that we use a Cisco 1700 series router and a CISCO 515E PIX.

Any clues will be greatly apprieciated.

Thanking you in advance,

Dimitris, Athens, Greece.

[Victor Pendlebury · Accepted solution]

Hi

Is the following applicable ?

http://support.microsoft.com/default.aspx?scid=kb;en-us;830471

You experience intermittent connectivity when you connect to a network from a computer that is running Windows XP or Windows Server 2003

Victor

[Dimitris Vayenas]

We discovered that in our Router one of the interfaces (the one that deals with the DMZ) has loads of collisions. (around 300/min).

We dont know the source. The idea is to debug the VLAN in our switch in order to see what is going on.

However our optical line gets converted to ethernet using a Nortel switch and initially it appeared that there is some kind of incompatibility between the router (1700 series) and the Nortel Switch (opto-ethernet). We switched the interfaces in our router and thought that we solved the problem. It may be though that the situation has to do with the interface on the router itself. In the next few days we going to upgrade to 2920 router and we shall see.

The error you mentioned above does not occur in our DMZ machines but used to occur in our intranet machines (Exchange 2003 actually) so we will give it a shot as well. I will call MS support first thing in the morning.

Thanking you for all your effort.

Dimitris.