Communication not happening after deleting other VMs with default SG - Packstack(Ocata)

Set up used :
Packsctack - ocata
ODL - carbon (karaf distribution created on 05/06)

3 odl cluster + 1 control + 2 compute nodes

Steps to reproduce:

1. Created 3 VMs (VM1, VM2 and VM3) with default SG
2. Verified the ping between VM1, VM2 and VM3. It works as expected
3. Deleted VM3 and verified the ping between VM1 and VM2

Expectation :
Ping should be succeeded between VM1 and VM2

Actual result:
Ping failed between VMs