Strange communication fail UDP COAP protocol Openstack Kilo

[CesarJorge]

Hi,

I have one UDP COAP application called ligthweight M2M in Openstack Kilo environment.

To communicate with this app I have one nginx cluster using pacemaker. This cluster use one VIP (10.0.0.6) and one Floating IP that communicate to outside (192.x.x.x).

The nginx entry is using stream definition for UDP.

The COAP application is in the internet at the url:

https://github.com/telefonicaid/lightweightm2m-iotagent

Then when I use the COAP client to communicate to server at:

https://fiware-iotagent-lwm2m.readthedocs.io/en/latest/configurationProvisioning/index.html

Then when I try to connect to server with the client (with all UDP security groups enabled ports),
then:

When I try to connect 10.0.0.6 string /string (throught the VIP), works correctly and connect.
When I try to connect 192.x.x.x string /string (throught Floating IP, all UDP ports open and ICMP)
Then fail to connect. Doing a strace in client process show that does:
create socket
bind
send
send
send
...
Here fails. The client stuck in send and try until timeout.
Using the VIP that working, does:
create socket
bind
send
receive
...

Also, I try the following that works:
Create a Floating IP and connect that assing directly to active nginx machine.
Create a Floating IP and connect that assing directly to server lightweigthm2m.

Not work througth a Floating IP that assing to VIP.
In the nging I try multiple configurations:
Using only one server, using balance hash, etc, without success.

Howto fix this, and what occurs?

Regards,
Cesar Jorge

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