Hello,

I am currently on a traineeship for a validation of a admin title, with a distribued monitoring project.

Central in a DMZ, securised by UTM

Pollers on each client side, securised by UTM

So the flux is like : CENTRAL <> UTM <> INTERNET <> UTM <> POLLER

I’m currently in the pre-prod phase, and i’m having issue with connecting Central / Pollers with ZMQ.

Obviously I dont have the creds of UTMs so the configuration isn’t made by me so I can’t verify as I wish… I know so far that there is a NAT / PAT configuration.
 

I followed the following post to troubleshoot my problem

I saw that ZMQ port (on central / poller side) dont have the same port

I digged more with netcat simulating server/client with 5556, CENTRAL normally send “aaaa” to POLLER; but it respond a weird thing “router-external” on CENTRAL and nothing showed on POLLER

 

So I’m here to ask, is that a normal behaviour from ZMQ? In my school I always been told that TCP request need a match on source port (generated randomly) that become destination port and the FAQ (link above) says the same.

Can anyone enlighten me on this please? Thx alot