Gentoo Causes Small Personal Router To Freeze / Lock Up

[SD Lead Sponge]

I recently installed Gentoo (2007 release) using the extraordinarily well written Gentoo Handbook to guide me through (very informative).

I can get the system to boot, but I am experiencing a very odd problem. And I don't know where to begin or even what information you will need, so please bear with me. It deals with networking (and is quite a crimp on emerge too)

I have a US Robotics Router (el cheapo). It acts as my default gateway, and a DHCP Server. I can successfully connect Fedora 6-8, Ubuntu, Knoppix, Windows XP, Windows 2000, Windows 98SE to this device without trouble (I can provide static IPs or request DHCP from the router). However, when I run gentoo (the box in question has already had all the aforementioned OS's installed/run except 2000 and 98SE), merely plugging the CAT5 cable into the NIC causes the router to crash. I have to powercycle the router to resume a connection from the nongentoo boxes (and unplug the gentoo box).

One major change I did make after installation was I had to recompile my kernel without the old IDE drive support. According to several good people on #gentoo (freenode.net) there was a bug when using SATA drives and having modules available for IDE. I don't think this caused an error, but maybe I removed a module I shouldn't have? I was unable to test the interface before the change, because the system could not mount root until I did.

Any ideas?
-sdls

P.S. I am new to Gentoo, I wouldn't be surprised to hear I set a compiler flag wrong or whatnot.

[frostschutz]

This should not happen unless your machine is defective and somehow your RJ45 port fries the router over the CAT5 cable due to an electrical problem or something. If the US Robotics router hangs or crashes (i.e. a software problem), it's an error with the US Robotics. And if that machine is closed source and a black box there is no easy way to find out what is causing it and how to debug. If you can rule out hardware failure, there is not much you can do, except maybe ask in a US Robotics forum?

If you're interested in Linux, you could spend like $50 on a Linksys WRT54GL or $80 on an ASUS WL-500-GP or a similar device. These routers run Linux, you can flash any open source distro (OpenWRT or whatever) on them, and it gives you more control over just about everything - especially proper debug messages / kernel panics in case something goes wrong at least you'll then know where to start looking for the cause.

[SD Lead Sponge]

frostschutz,

I understand why you're saying that and normally I would agree with you, however, after those problems, I installed Ubuntu on another partition and the NIC came up without problems (WinXP too). I used the same Ethernet Cable, the same router, the same usb ports plugged in, the same computer, the same everything except distro. However, the moment I turn on Gentoo (Ubuntu wasn't all I had hoped for), the router crashes.

I am quite interested in Linux. I've been an avid Fedora user for the past several years. I am currently looking at other distros for a broader perspective and understanding in the availability (it is also helpful in my job). I'll consider those routers, it would be nice to have a message log that provides useful information.

[Rad]

Yes, well... it sure seems weird, but Gentoo does nothing "special" there.

It's quite possible that you configured the kernel's networking settings differently, or use a different DHCP client or something like that.

Unfortunately, there's probably not much you can do to diagnose the problem besides reading wireshark / tcpdump logs on both machines and start manipulating things, if you happen to be able to do that (that's a nontrivial thing to do).

You could also switch / alter kernel options at random and pray that helps - or just switch hardware, as frostschutz suggested.

[SD Lead Sponge]

Ah, oops. Sorry about that. After rereading my last post it could be interpreted as "Gentoo is a piece of crap, it is messing up my network." That was not my intention. I was referring to the networking components and was quite convinced I had made an option wrong in the installation, not that Gentoo was garbage. Or, as Rad mentioned, something is wrong with my DHCP client or interface.

I believe I found the culprit. After performing a tcpdump with another linux box sniffing the gentoo, it looks like my gentoo box sends out IPv6 Router discovery calls before sending out IPv4 requests. Given the low cost and age of the router, it is most definitely safe to say that the router crashes upon IPv6. Unfortunately, I believe I compiled IPv6 in the kernel, and didn't include it as a module. So unless if I am mistaken, I'll have to do a recompile. Is that correct?

-sdls

[frostschutz]

IPv6 or IPv4 shouldn't matter to the router... and unless you configured a very custom kernel with Ubuntu or whatever, this will come with ipv6 support as well. All you can do is guesswork Gentoo or Linux nor any other software should be able to crash independent network devices just like that. If this was possible you couldn't run open networks like at universities and such.

Oh yeah, I forgot: Maybe its a known bug on US Robotics side and there is a firmware update you have not yet flashed on the router? Or maybe you did update and the new firmware introduced some bug so you h ave to go back to an older one?

This is the only thing you can actually try...

Other than that, get a device that can tell you (or at least tries to) what is going wrong...