Description of problem:

Customer not able to ping/send/receive traffic outside the host after migrating VM's from RHEL 6.6 to RHEL 7 hosts.


Version-Release number of selected component (if applicable):

RHEVM 3.5
qemu-img-rhev-1.5.3-60.el7_0.11.x86_64                    

How reproducible:

Customer trying to upgrade to RHEM 3.5 and RHEL 7 host.

Steps to Reproduce:

1. Guest rhel 6.5 vm running on hypervisor os 6(RHEL 6.6)
2. Try and migrate to upgraded hypervisor(RHEL 7)
3. No network after successful migration. Vm also paused
4. Shut down vm ungracefully
5. Boot up vm on old hypervisor(RHEL 6.6) cluster
6. Upgrade rhev tools from repository
7. Live migrate to new upgraded hypervisor cluster
8. Migration successful
9. But no connectivity outside of host. Can send/receive traffic to VM's
   connected to same bridge(rhevm) and host.

Actual results:

VM not able to connect outside host.


Expected results:

VM should be able to connect outside host.

Additional info:

It looks like ARP cache is not getting updated inside guest.
Only workaround worked for Customer id to ad a new vNIC(Virtio or e1000) and attach this NIC to different bridge interface. After doing this VM can ping outisde host as well.