Ok I've bee searching forums all day with no luck. I'm in a real mess, although one that might possibly have an easy fix.

On my network I have a bunch of machines running either Windows or some version of Ubuntu. All of these machines can connect to my router via wireless.

I also have a machine running Ubuntu Server 10.04.2. This machine does not have a wireless card and is connected directly by ethernet cable to the router.

All of the above machines have been configured in the router as having static IP addresses.

Recently, on the Ubuntu Server, after a combination of trying to get KVM to work and also installing 2 additional ethernet cards (which have since been removed) I lost the ability to ping external IP addresses. DNS seemed to be still working (hostnames would resolve when pinging, but ping would fail), and I could ping internal machines with no problems.

After a bunch of troubleshoting, I also lost the ability to ping the gateway or any internal machines. Not to mention I also stupidly removed dhcp-client (although dhclient wasn't helping before)

Despite DNS no longer working, resolv.conf looks fine. Routing tables had default routes pointing to the correct gateway for both eth0 and br0 (not sure whether br0 should be involved or not)

As of the latest update, I'm no longer getting an ipv4 address despite having set a static one up in /etc/network/interfaces

I tried blacklisting ipv6 in /etc/modprobe.d/blacklist but still getting ipv6 addresses only.

My interfaces are br0, eth0, lo and virbr0. I'm pretty sure br0 ad virbr0 showed up after I installed KVM. eth0 is my ethernet.

I would just reinstall the whole system, but I'm hesitant to do so since I had backed up so much stuff onto this machine before this happened.

Currently I'm in the process of trying to set up an offline repository so I can attempt to get dhclient back, but in the meantime, what else can I do to troubleshoot this?

Is there a recommended config I can try? Or a script/wizard that could automatically configure it?

Would it be helpful to disable kvm or remove br0/virbr0? (if so, how?)

Are there any logs I can provide? (copy/paste won't be helpful but maybe I can output to a file and get it onto a usb drive or something)