[PVE-User] vm lan card stops working

[Muhammad Yousuf Khan]

i am using kvm guest providing squid services on this VM. there is the
layout of my network and vm.




local LAN : <----------> eth0/vmbr0 (squid) eth1/vmbr1 <------------->internet

i am using this linux vm for 4 weeks with no issues but today
something un usual happen. users started reporting me there internet
is not working

i ssh the vm and ping the outside host or gateway it gives me
"icmp_seq=0 Destination Host Unreachable"

however other VMs on same box could ping the outside host. and the
point of confusion is it stops reaching the internet automatically .
and i did several restart nothing helps. i delete the VM lan and added
the new one. with not lock at the end.

but finally things started working again. and i haven't touched anything.

what do you think what could be the reason and how to resolve it. i
which that i would know what was that because i was in a handicap
situation and i coudn't realize what was the problem since vmbr1
through base machine was working fine. but base machine couldnot reach
the eth1 of squid. so i am worried and a bit scared too.

Thanks