Need network advice--I think

[Ohioguy]

I this is a network question, but point me elsewhere if I'm wrong.

I have two computers connected with 10 mb/s ethernet running through a hub. One is running NT 4.0; the other I just converted from Win95 to Win2K Pro with a clean install on a new HD. This problem has only occurred since I made that change. Before that, these two computers worked happily together for a year.

The problem is that when I copy files from the NT machine to the Win2K machine, some of them don't work. Most files--text files,WP documents, etc. are fine. But some files--such as executables and data exported from my financial trading system, just don't run right on the new machine.

If I bring the file across on a floppy, it's fine. But copy it across the network, and it doesn't work. The file sizes and dates remain the same, but there seems to be some kind of corruption creeping in, and because it only happens when copying across the network, I blame the network.

If I copy the file back to the NT machine, it still won't run, again confirming that somehow the file is different after the copy. I am completely stumped as to why certain kinds of files are always unscathed, while others are always corrupted. It is clearly related to the kind of file, rather than to size. Oh, and the errors that I get from running the corrupted files are not always the same, even when copying the same file repeatedly. But if I file comes across corrupted, it will always come across corrupted. I do check to see that the original files are OK.

I've tried a lot of things, too many to list unless someone asks. I'm over my head, here. Please help!

--Chris

[M_Six]

Ohioguy,
That is bizarre alright. I have an NT/Win2k network and I can copy files fine. A little more info might help. What SP are you running on the NT box, and what protocol are you using on the LAN? Also, (and this shouldn't matter, but just in case) are the partitions on either end different? I.E., is one Fat32 and the other NTFS or something?

[Ohioguy]

M_Six, thanks for helping out, here.

One of the first things I tried was to upgrade both boxes to newest SPs. So it's NT4.00.1381--which is SP6. The W2K box is SP1.

Protocals to the NIC on the NT bx: Netbeui, NWlink IPX/SPX Compatible transport, TCP/IP.

Protocals to the NIC on the Win2K box: TCP/IP, Netbeui.

I'm not very familiar with protocals, so if I didn't answer the question as you meant it, let me know.

Both boxes are NTFS. The Win2K box was running Fat32 before, when it was a Win95 box, but as I mentioned, I threw out the HD and started from scratch. Weird that everything worked before that change.

I've learned a little more about the file corruption. As mentioned, file sizes stay the same. But looking at the original vs. the copy in a hex editor, blocks of code are missing (or maybe just different, but I think missing) in the copy. If I copy repeatedly, each copy is corrupted in different places--no two are alike. Apparently, some files are sufficiently fault tolerant that this doesn't matter, though it renders other file types (such as executables) unusable.

Every time I do a copy, the collision light on my hub blinks on at some point. But a few collisions are to be expected, aren't they? No cables are coiled or anything, and nothing physical was changed when I swapped OS's on the Win2K box.

I note that the NT box thinks the Win2K box is running NT 5, in case that matters. I don't see a way to tell it otherwise.

The Microsoft knowledge base mentions editing the registry to increase the delay between packets, but this is in reference to 100 mgps networks, and mine is a 10mgps. Obbiously not something I want to do unless a more knowledgeable person suggests it might help. But I have wondered about it.

Any and all ideas are welcome. Thanks!

[obenton]

Could be a NIC problem. Try setting NIC configuration to 10BT, half-duplex (from default, which is usually "Auto"). Check NICs in the MS Hardware Compatibility List for the OSes, and make sure you've got the latest drivers. And check device manager and make sure they're not sharing an IRQ. If all else fails, post NIC info and where they're located on the motherboards.

[M_Six]

Ohioguy,

I agree with obenton. If that doesn't solve things, try different CAT5 cables. Sometimes a minor flaw in a cable is enough to wreck data. There's little doubt it's a network issue, and network hardware problems are the easiest to check and resolve. Let us know.

Also, if you don't need the IPX protocol, dump it.

[Nighthawk]

Some programs use registry information to function (This could explain the executables not working.) If your financial software uses registry hooks to verify the files you are using, that could explain why they, too, don't work.

[M_Six]

I was thinking that, too, Nighthawk. But he said if he uses a floppy to transfer the files, they work fine, so the registry shouldn't be the issue.

Ohioguy, this may sound like a dumb question, but how are you moving the files from one PC to the other, straight Copy/Paste, or are you using some sort of ftp utility like FTP_Explorer? The reason I ask is that if you ftp executables in ASCII mode, you'll get the same results you're getting. Just a random thought.

[This message has been edited by M_Six (edited 03-10-2001).]

[Ohioguy]

Thanks for all your suggestions. I tried them all. So far, no dice:

I don’t see any way to change the NIC configuration. That would be done in device manager, wouldn’t it? There are no choices, there.

The Win2K box in question is a laptop, so the NIC is a PCMCIA card, in a mini-dock. There have been no changes in this hardware since the setup was working under Win95. NIC is a Linksys Combo PCMCIA card, model EC2, cigar shaped, 3 LED.

MS lists my NIC as compatible, and Linksys site says they’ve tested it with Win2K. Linksys and MS both say to use the driver that comes with Win2K, which I’m doing.

Can’t find any interrupt conflicts, and device manager says the device is working fine. This is all on the Win2K box, which I’m concentrating on because it’s the one I changed just before the problems started.

I dumped the IPX protocol.

I’m doing the copying using straight cut and paste. I tried shelling out to a command prompt and using the copy command, and got the same results.

Oddly, the corruption only occurs when I copy from the NT 4 box to the Win2K one. Going the other way, no corruption at all. And the collision light on the hub only comes on during the transfer to the Win2K box—and then only when the file is “pulled” by the Win2K box. If it is “pushed” from the NT box, there is still corruption, but no collision light, and there is an error message: “Cannot copy [name of file]: An unexpected network error occurred.” In spite of that message, the copy is there, but corrupted.

I agree that the registry is probably not the issue. When I first posted my question, I hadn’t examined the files in hex, and I couldn’t understand why some files were corrupting and some weren’t. Now (using a hex editor and file compare utility) I’m sure that nearly all are bad, but some programs are fault tolerant enough that it was less obvious. I just checked a Word document, and it corrupted during the copy.

Also, if I copy a small file (22K) repeatedly, every once in a while one comes through cleanly. A larger file (93 K) is always missing some data.

No change from swapping in a fresh cable for either of the ones in use. Ditto for changing ports on the hub.

I'm open to more suggestions! And thanks, again, folks.

[Ohioguy]

At last, some progress. I find I can get things to work if I move the NIC from the mini-dock to the laptop itself. Don't know why, but now I can at least my work done while I figure it out. When NIC is in mini-dock, device manager says it's ni PCCard slot 0. When in laptop itself, device manager says it's in cardbus slot 0.

I don't know what the difference is between "cardbus" and "pccard." Maybe PCcard isn't compatible with Win2K? Maybe there is an interrupt conflict for the drivers for PC card or cardbus?

Anyway, thought I'd post this progress, so that nobody has to waste time barking up the wrong tree. Thanks again for the help, and I'm happy for any more advice that you have.

[M_Six]

Ohioguy,

What brand/model mini-dock are you using?

[M_Six]

Ohioguy,

I checked with a networking guru friend of mine who said that TCP/IP and Netbeui don't play nice when combined in an NT/Win2k environment. He said you shoudn't need Netbeui for anything. If that's true, try dumping it from both machines and go with TCP/IP only. Let me know how you fare.

[Ohioguy]

When I dump Netbeui, I can't see or be seen by the other machine. Apparently it is needed by Microsoft Networks? Is there another type of network I should be using, in order to go with straight TC/PIP?

[M_Six]

If you're not on a domain, you may indeed need Netbeui for the machines to see each other. If you are logged into a domain on both machines, Netbeui should be unnecessary.
Hmmm. Just for testing's sake, before/if you reinstall Netbeui, can you try mapping a shared folder on one PC to the other and then moving files that way, so the "K" drive on the NT box is "share1" on the laptop, or something similar? You may have to type it in manually, as the laptop isn't showing up in Network Neighborhood. If you can map a drive successfully, try moving a file from the C: drive on the NT box to the mapped drive.

[Ohioguy]

M_Six,

It's a Gateway Laptop, a Pentium 166 from August 1997, with the mini-dock that came with it.

Box is Gateway 9100 Solo (no designation like SE or LS) 13.3" screen, revision E 2.1.

Mini-dock is Gateway F2.01/BFPV, P/N 8001361.

Gateway doesn't have much to say about this problem, as they don't support Win2K for this device. They did publish a bios upgrade for Win2K, which I installed before loading the new OS.

I'm going back to the MS knowledge base, now that it appears to be a PCMCIA card problem. Gives me some new search words. Of course, for the last few days, searches for the Win2k product haven't been returning anything at all, so that might not help.

I did try uninstalling the PCMCIA slots in device manager, then letting Windows reinstall them. Didn't help.

[Ohioguy]

M_Six,

No can do--without Netbeui, I can't even map a drive manually. In fact, my existing drive mappings go the way of the dodo.

I can unbind TCP/IP from the NICs, but the problem stays.

I keep thinking that, since the NIC works in a cardbus slot but has problems in a PCcard slot, maybe there is a problem with the implementation of PCcard slots in Win2k. I can't get the MS knowledge base to return any articles on Win2K--I don't mean "articles on this subject," but any articles at all. Maybe if they ever fix it, there will be a mention of this.

[M_Six]

Ohioguy,

You're probably right. I have a Dell laptop and docking station. Everything on the docking station works except the speaker jack. I have to use the speaker jack on the laptop itself to get sound. I have Win2k on the laptop. Maybe there really are issues with Win2k and docking stations. I'll look in TechNet and see if anything comes up. Sorry I couldn't be more help.

[Ohioguy]

M-Six,

I really appreciate your efforts. Please let me know if you find anything more.

[defcon1]

Have you looked possibly at the speed of the hard drive you are using on the win2k box? 5400RPM vs. 7200RPM? I had a friend once that bought a 7200 RPM hard drive, and tried to burn cds from files on the hard drive. The CdBurner would go through the process fine and the files would show up, but because the board thought that it was a 5400 drive, the files would never run or play. If he burned a cd from the 5400RPM drive in the same box, on a different IDE controller, then they worked just fine.

[Ohioguy]

Hadn't thought about that one. It would mean that the Cardbus slots work with the HD speed, but the PCcard slots don't...

Would have to call Gateway and find out what speed the old drive was, as I tossed it out. It was crashing, which was the catalyst for the upgrade in the first place.

If HD speed did turn out to be an issue, I wonder if there is a fix short of another HD replacement? Something to edit in the registry?

Incidentally, I have a message into Linksys tech support (it's their NIC,) & will report if they follow up.