Comment 17 for bug 1708731

I found another problem about refresh firewall caused tcp link unstable。
env： tenant_network: vlan mode
This is my reproduce step
1.Create a security group named test, with 6 rules which are icmp/tcp/udp ingress/egress passed to cidr 0.0.0.0/0, and a rule which is icmp ingress passed to remote security group test.
2.Create a network and subnet, both named test
3.Create 4 vms(vm1, vm2, vm3, vm4) in compute node-2 with network test and sg test
4.Create 2 vms(vm5, vm6) in compute node-3 with network test and sg test
5.Create a large file in vm5: dd if=/dev/zero of=/mnt/test.img bs=1G count=15
6.Copy the large file into vm1-4 from vm5: scp <vm5-ip>:/mnt/test.img /mnt/
7.Edit vm6's security group, remove the test sg
8.Tailf the openvswitch-agent.log in node-1, you will see "Refresh firewall rules" print
9.Login to vm1-4, you will find the scp process status becomes to stalled

You can do step6-step7 for many times to reproduce the problem.

Seems refresh openflow will cause tcp link unstable.