Connection issues between fixed private IP and floating ip

[Marius L]

I have a single node deployment of Openstack Liberty.
The L3 Agent is on dvr_snat mode.
I have a global Flat network which is external and is used for floating ips, and for tenant networks I use VXLAN.
I have 2 VMs (VM1, VM2) connected in a VXLAN.

Case: VM1 has a floating IP assigned. VM2 has no Floating ip assigned.
- Ping VM2 -> VM1-Floating-Ip works, and says that response is coming from VM1-Private-Ip (expecting response from VM1-Floating-Ip)
- Ping VM2 -> VM1-Private-Ip works as expected
- [*] Curl VM2 -> VM1-Floating-Ip does not work. It freezes on a "connecting" state.
- Curl VM2 -> VM1-Private-Ip works as expected.

Case: VM1 has a floating IP as well as VM2 has a floating IP.
- All the scenarios from the previous case works as expected.

The problem is when VM2 has no floating IP and try to connect to VM1-Floating-Ip. Here the ICMP requests works, getting response from VM2-Private-Ip, but the TCP communication does not work. I can understand that the router doesn't allow the Packet to reach the outside world through the SNAT because the destination is on the same private network, but I cannot understand why the TCP communication is not working between VM2-Private-Ip and VM1-Floating-Ip.

[Armando Migliaccio (armando-migliaccio)]

I believe you're experiencing bug 1462154, can you confirm please?

[Marius L (marius-leus)]

Yes it's the same behavior, so I confirm it duplicates bug 1462154.