Did something happen in the last day or two that would have
screwed up libvirt networking? I just started up a VM
that I last ran on Sunday and it has suddenly developed
issues with communication with the host machine.
Call it VM1 and VMHOST (the libvirt network) and VMHOST_EXT
VM1 ping -> Internet works
VM1 ssh -> Internet works
VM1 ping -> VMHost single ping goes through
VM1 ssh -> VMHost works
VMHOST_EXT ping -> VM1 works
VMHOST_EXT ssh -> VM1 fails
The only things that have changed were Ubuntu security
updates to VMHOST (It is an Oneiric).
The VM1 is intentionally kept unchanging to avoid
breaking some software which will not work on newer
releases (jaunty).
Again, I was using the VM and mounting fs from VMHOST
on it as recently as Sunday.
Either there is something deep inside Ubuntu that has
gotten deeply confused or someone has released an
update that breaks things.