Attempted email download disables network connections.

[Happo]

Hi all. I was hoping someone could shed a little light on this problem I have been having for several months.
I am in an office with an all xp pro workgroup. One machine has an issue with downloading large emails (1Mb+ or thereabouts). When attempted from either Outlook Exp. or Thunderbird it begins to download (I can see router lights flashing) then suddenly stops, giving no errors at all, the message does not complete downloading. Now here's the annoying bit, after it 'stops' I can no longer access the internet or the local network. Look@LAN shows my IP in Yellow with lots of ???, not appearing online(green) or offline(red). Even logging off does not help the networking situation, I have to do a full reboot before it is all back to normal, then use webmail to download and delete the large message in question.
I did some research and played with MTU settings but nothing makes any difference. I also contacted our ISP who, although very helpful (yes, really!) were unable to fix or offer any explanation as to why this may be happening.

Ideas?

Thank you in advance.

Daniel.

 

[bcastner]

Replace your network adapter.

 

[Happo]

Umm, not saying you are wrong but that sounds a little extreme and I wouldn't do it just to fix this issue. Everything else networking wise is working perfectly. The computer in question also uses the integrated ethernet port (Gigabyte M/B) so it would be a new, rather than a replacement adapter. Can you tell me what you are actually thinking the problem may be so I can do some research.

I should also say all smaller (<1Mb) emails download fine and downloading from the net is no issue at all.

Thank you.

Daniel.

 

[bcastner]

When attempted from either Outlook Exp. or Thunderbird it begins to download (I can see router lights flashing) then suddenly stops, giving no errors at all, the message does not complete downloading. Now here's the annoying bit, after it 'stops' I can no longer access the internet or the local network. Look@LAN shows my IP in Yellow with lots of ???, not appearing online(green) or offline(red). Even logging off does not help the networking situation,....

Replace the network adapter.

To be completely fair, this could be an MTU issue. The only sane way to handle them is to test them first:

. Test:

http://www.dslreports.com/tweaks

Note the MTU and RWIN values. Then use:

. the freeware DrTCP utility:

http://www.dslreports.com/drtcp

Best wishes to you Happo,
Bill

 

[Happo]

Thanks for the links but I have already been down that path. I have tried many different combinations of MTU & RWIN to no avail.
The controller/device driver is the latest version and the system is SP2.
I guess I just find it hard to believe a system can perform flawlessly, apart from this problem of course, if the network adapter is faulty.
I do some regular (twice/week) very large network transfers 20Gb+ to and from this system without a single glitch, no fancy third party programs either, I do the transfers manually from within Windows.
Thanks anyway.

Daniel.

 

[bcastner]

Happo,

Do an ipconfig /all to identify the network adapter at the chipset level.

Then rather than use a driver from D-Link, Linksys or whetver, find the OEM chipset manufacturer and use their web page to find a better driver.

ADMTek and others all offer driver support.

 

[Happo]

Then rather than use a driver from D-Link, Linksys or whetver, find the OEM chipset manufacturer and use their web page to find a better driver.

Already using the latest driver from the Manufacturer - Marvell Yukon 88E8001/8003/8010 Gigabit Ethernet Controller (released 01 Feb '05) .

Daniel.

 

[linney]

Stay with "Bcastner" on these type of problems, he is the best.

I was wondering if you had considered any virus or malware scanner that might be causing problems with the excessive size e-mails? Perhaps you could test that if it is possible to repeat the fault or do you have to wait for a large e-mail to arrive?

Buffer overflow comes to mind but I don't know enough about that to take you anywhere, only to suggest that you make sure everything is fully updated.

 

[Happo]

Thanks linney, it hadn't occured to me to try shutting down the various virus/malware scanners on the system. I am not back on site until Monday, I will send an email from another account with the aforementioned scanners offline then and see what happens.
Let you know.


Daniel.

 

[Happo]

No go. Have tried everything I can think of, including linney's suggestion above and nothing has changed the behaivour at all.

Oh well. Thanks anyway.

Daniel.