[solved] amd64 ethernet/routing with 8gb of ram

[chkrimmer]

After upgrading memory from 4gb to 8gb the network stops working. My machine is a nforce4, amd 64x2 5200+ with 8gb ecc ram. The ethernet (forcedeth) is recognized and configured, routing tables and ifconfig output are OK, but no packets are sent/received. I searched everywhere, tried IOMMU options already (kernel only runs if it is activated).

The memory is completely recognized by the kernel (3GB low, 5GB high). If I run the 2007.0 gentoo livecd, the behaviour changes a little bit. With this kernel, I can ping the gateway, but not the computers on the local net. There the setup looks like

Computer: 192.168.14.9, mask 255.255.255.0, gateway 192.168.14.1
Other computers available: 192.168.14.3, 192.168.14.7, 192.168.14.8

The command traceroute shows that packets to 192.168.14.x are sent to the gateway... although the routing table shows an entry for the local network.

If I remove 4gb of ram, anything is working.

Any suggestions how to get the network up and running with 8gb of memory?

Thanks in advance.

PS: I played a little more with the kernel options. It runs with 8mb installed, and the kernel option mem=7GB, limiting the used memory to 7GB. So how do I get the remaining GB of memory?

[chkrimmer]

Ok, the problem has vanished after switching to kernel 2.6.22...

Best regards.