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ISA Server 2004: Put in T1000 switches - now got problems !

SpencerSteel asked
Medium Priority
Last Modified: 2011-09-20
Hello there,

We have a small single domain network - vanilla MS stuff - with an ISA 2004 gateway. Clients use IE and Firewall clients.

It was all connected via unmanaged T100 'superstack' hubs but at the weekend I replaced everything with T1000 switches.

Since then I've had problems.

The clients will very frequently (say, once at hour at least) slow right down or get the ISA webpage unreachable '404' type page.

A restart of the ISA Services sorts it. It's very quick again ... for a while.

I get this even with a client that's directly connected into the same T1000 switch as the ISA Server.

Now, i'm a notive with this stuff - and no firewall expert, so I'm a bit stuck.

As these switches have IP addresses - do you think there is some sort of routing problem? Does/should ISA rebuild the routing tables?

I really can't think what else has changed ... but it's is a REAL problem for me ... any help would be appreciated as I don't know where to start. I've checked the obvious - DNS etc and everything is resolving well. There are no errors in any event logs that I can see.

Kind of desperate ... many thanks ...

Watch Question

Once you had the switches in place did you happen to move your cabling around in different ports on the swithces? Do this, when you can, cut your switches off and power them back on. See if your problem goes away.
Keith AlabasterEnterprise Architect
Top Expert 2008

Doubt if this is a routing issue. Certainly won't be a firewall issue if you have changed nothing. The exception will be if you have used IP addresses on the switches that conflicy.

for example, if your interanl LAN is on 192.168.0.x and the external LAN is on 10.0.0.x. If you have put a 10.0.0.x address on the inside or a 192.168.0.x address on the external side it will be unhappy.

Check the interface settings on the switches. and compare against the network card on the ISA server. Same speed, duplex setting etc.


Just to follow up - this has turned into a M$ 'pay-per' incident.

They are helping me work on it - so far many hours have been spent and we are not exactly sure what the issue is.

I'll let you know when we find out.



OK...problem solved, basically it was a problem with the LAN cards driver and the 'virus throttle' service, which is something that HP put on the NIC card on these pre-built ISA Server DL320's.

Updating all the drivers sorted the issue.

Very simple solution but something we all (including M$) overlooked.

PAQed with points refunded (500)

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