Strange Problem

[Guest]

This issue comes and goes on a few PCs.

I can log a computer onto our domain and everything accesses fine...
Exchange 2003, Citrix apps and Internet. Then the next time they log in,
Exchange works and Citrix and the Internet are not available. A day or so
later, they might work again. There is no pattern.

Thus far, swapping out NIC cards has helped to remove the issue temporarily
but it has come back on a couple of PCs. I am also having this issue on a
couple of laptops and can't swap NICs.

We have several locations in our network and this is only happening to a
select few PCs at a couple of locations.

Any ideas?

 

[Frankster]

This issue comes and goes on a few PCs.

I can log a computer onto our domain and everything accesses fine...
Exchange 2003, Citrix apps and Internet. Then the next time they log in,
Exchange works and Citrix and the Internet are not available. A day or so
later, they might work again. There is no pattern.

Thus far, swapping out NIC cards has helped to remove the issue
temporarily
but it has come back on a couple of PCs. I am also having this issue on a
couple of laptops and can't swap NICs.

We have several locations in our network and this is only happening to a
select few PCs at a couple of locations.

Any ideas?

DNS issues. Make sure all DNS entries in servers and clients are configured
correctly. Specifically, internal machines (including internal servers and
internal DNS servers) should have TCP/IP configuration to only point to
internal DNS server(s). The internal DNS server(s) should be configured to
forward to the external DNS server(s) (provided by your ISP).

Typically, the only place you will need the ISP provided DNS server IP
configured into the TCP/IP properties is on one device, the router with the
internet line coming into it.

Don't be confused because your problem is "intermittent". The intermittent
nature of this problem is exactly the symptom of a mis-configured DNS
architecture. The most common mistake is putting both internal and external
DNS IPs into the internal machine's TCP/IP properties. Don't do that.

-Frank

 

[Frankster]

Oops... correction... Last sentence, my 1st paragraph:

"The internal DNS server(s) should be configured to
forward to the external DNS server(s) (provided by your ISP)."

SHOULD READ...

The internal DNS server(s) should be configured to
forward to the ROUTER IP, where external DNS IPs provided by your ISP are
configured.

-Frank