Hello all,
Just purchased an ecs 6100sm-m geforce motherboard
based on the nforce 405 chipset, and using the MCP61 onboard NIC.
I'm running gentoo linux, and kernel 2.6.19 (the gentoo version 2.6.19-gentoo-r5). The driver I'm using is the forcedeth module in the kernel.

I noticed I had fast access to my departmental intranet, but very slow (bytes/s or stall) to the rest of the internet, via http, sftp, rsync. I ran traceroute from my computer, and another box on my intranet.

From working computer:
harris@rabi:~$ traceroute gpu.srv.ualberta.ca
traceroute to gpu.srv.ualberta.ca (129.128.5.145), 30 hops max, 38 byte packets
1 129.128.128.1 (129.128.128.1) 0.429 ms 0.357 ms 0.325 ms
2 129.128.153.53 (129.128.153.53) 1.273 ms 0.682 ms 0.645 ms
3 129.128.3.205 (129.128.3.205) 1.410 ms 1.164 ms 1.145 ms
4 login1.srv.ualberta.ca (129.128.5.145) 0.890 ms 0.699 ms 0.629 ms
But from new box:
traceroute to login1.srv.ualberta.ca (129.128.5.145), 30 hops max, 46 byte packets
1 129.128.128.1 (129.128.128.1) 0.367 ms 0.313 ms 0.297 ms
2 129.128.153.53 (129.128.153.53) 1.142 ms 0.652 ms 0.618 ms
3 129.128.3.205 (129.128.3.205) 8.909 ms 4.158 ms 1.125 ms
4 * * *
5 * * *
6 * * *
7 * * *
8 * * *
9 * * *
10 * * *
11 * * *
12 * * *
13 * * *
14 * * *
15 * * *
etc.
Seems like packets get held up at 129.128.3.205, while from the working box, they fly straight through. I'm currently using squid on the first box as an http proxy, which makes web access fast again, but this is only a partial solution.

I figured maybe since the MCP61 such a new chipset, the forcedeth module was not quite fully developed yet, so I plugged in another NIC in a PCI slot. I disabled the onboard NIC in the BIOS, and threw in a Realtek Semiconductor Co., Ltd. RTL-8169 gigabit card, and built the r8169 module. Unfortunately, I get the exact same results.

I don't see anything interesting in dmesg, anybody have any ideas? Seems like something is causing my tcp packets to have trouble being bounced around the net, any kernel options I could set to fix this? Any sleuthing to be done to figure this problem out?

I'd really appreciate any help on this one, my networking knowledge is pretty limited.
Kris

p.s. I did update the BIOS to the newest as a check.