Corrupted Large HTTP Downloads With New Router?

[tigeraid]

So I had a no sync issue a couple of weeks ago. Tech came out, said the modem was bad (and it was a very old SMC one), and replaced it with one of the new Cisco DPC3825s. Performance looks great, tests are good, streaming is good, torrents are good, FTP is good... Ping tests come back fine. Online gaming hasn't had any problems at all.

But any large RAR and EXE files I download off of websites (HTTP) get corrupted. RARs often give incomplete errors when extracting, and EXEs often get bad CRC failures.

This is pretty consistent with files over 400-500 megs, regardless of the source of the download. Are there any obvious things I can check? The modem is still set up default, however I have made this PC the DMZ (since it's for gaming.) Which makes it even more confusing because I thought DMZ would pretty much prevent anything from interfering with the connection to this computer.

I've tried the default MTU (it says 0 = 1500 bytes) and also tried 1492. I've turned SPI (Stateful packet inspection) off. It happens on both my PC and the wife's.

It's aggravating, to say the least, since this is the main way to download mods and tracks for simracing!

Any suggestions, folks? :|

[Alan P]

I wouldn't recommend making the PC the DMZ?

Is there a firmware update for the Router?

[thesameguy]

I have actually heard of that happening before. A firmware update on the router seems a likely candidate. You might also check that you don't have a firewall or AV software on the PCs that is causing this, as more than one PC-based firewall software is known to do this as well. Maybe something auto-updated coincidentally with the modem replacement...?

[tigeraid]

As I mentioned, it happens on both PCs in the house. So I don't think AV or firewall on my end would cause it.

And scratch what I said earlier, it DOES affect FTP transfers too. It doesn't affect torrents because, of course, torrents can re-do corrupt packets or whatever as they process.

I will look in to a firmware update I guess. :/

[tigeraid]

Tentatively, it appears that going to bridge mode and hooking up my old Netgear fixed this issue.

Though I sure would have preferred to find the "right" fix in the Cisco. Oh well.