neurological dryer lint

i had some fun with my network card issue on my laptop today. the scoop:

my onboard network card (a Realtek RTL8139C+) works perfectly except in one respect: in windows, when i try to transfer a file from my machine to another machine on the network, larger than, say, 500kb, the transfer starts and then 'times out'. that's in quotes, because sometimes it successfully transfers the file, or at least byte-wise the files are equal in size. sometimes it hangs and no file ends up on the destination machine. this happens on every LAN segment i plug it into - at home, here at work, on campus, etc. i've swapped cables, switches, no go. it happens with every protocol - windows filesharing (SMB), FTP, WebDAV... kermit.. zmodem... okay those last two are lies. and incredibly archaic geek reference jokes.

this seems to only occur when transferring files to other machines on my same subnet, i.e., 192.168.0.0/24. i can FTP a large file to ftp.bootleg.org from the office, for example, without problem.

smaller files work fine. downloading files works fine. normal operations (i.e. browsing, sending mail, AIM) works fine, and those all usually involve sending packets back upstream.

it works in linux. i boot to a linux live CD (say, gnoppix), mount my NTFS drive, and i can transfer files perfectly fine, no problems of any kind.

anyway. my first step was to contact the (useless) HP tech support. their solution of 'reinstall windows or send us back the laptop' was less than helpful. it seems too precise to be a hardware problem. although windows being damaged is a possible explanation.

next, i contacted realtek. they're in taiwan. their tech support engineers, however, were suprisingly coherent and adept with english. funny, HP's aren't, and they're 8 trillion times the size of realtek. anyway. so their first guy tells me to get the latest drivers. done that, doesn't work. i call them a few weeks later (today) and the first person i get starts helping me do large-packet ping tests and asks me questions. he settles on thinking, it's either windows or a hardware problem. windows, though, doesn't seem likely, as i can transfer files fine with my wireless connection. maybe it's a wired-ethernet-only issue in windows.

so then i decide, let's test that, i tried four (count em) different PCMCIA ethernet cards. NONE of them would pull an IP address from my network. manually assigned, and i can't talk to anything. granted, i've never used my PCMCIA slot on this computer ever in the last year. so maybe that's broken.

so my conclusion is that it's windows. which is apparently broken to disallow PCMCIA network cards from working at all, and from allowing me to transfer large files to systems on my local subnet.

that's all. i figured i'd document this so later when i set the building on fire, you know why.