Hello @ezohiko,
Which version of Centreon are you using and what is the error message when you try yo register the server ? Also, is your central authorized to connect to your remote server ? (or the opposite)
Regards.
The 2 servers are in 21.10.3
My central can not connect to the remote, because it is behind a firewall, and I can’t allow connection from the outside.
The message is : 2022-02-22 14:31:27+01:00 - ERROR - 10.8.0.2: {"code":500,"message":"API calling the Central returned a Server exception : HTTP\/1.1 500 Internal Server Error returned for \"https:\/\/xxxxx\/centreon\/api\/v21.1\/login\"."}
Hello @ezohiko,
if I resume:
- The Central cannot connect to the Remote Server
- The Remote Server can connect to the Central
Is that right?
Consider the distributed architecture available under https://docs.centreon.com/docs/installation/architectures

We have 02 network flows:
- The connection from Poller to Central is made by centengine on port 5669
- The connection from Central to Poller is done by gorgone on port 5556
In your IT, the connection from Central to Remote Server is not possible.
You have to start the gorgon connection from the poller.
You can follow this documentation:
https://github.com/centreon/centreon-gorgone/blob/develop/docs/poller_pull_configuration.md
Yes it is my configuration.
Can I add the remote server in the interface or must I add directly in the files ?
I look at a documentation but I don’t find anything revelant.
Hello @ezohiko,
We have an article on this topic coming up next week. As soon as it is available, I will let you know 
Regards,
Hey @ezohiko, Hello, here is the article that came out earlier than expected. I hope it helps 
The article is for a remote poller not a remote server.
I tried it but it’s fail.
@ezohiko You said it failed. Can you say more? where exactly does it fail?
Regards.
@Fabrix Hello is there also posible connect remote server over the internet to the Central?
i don’t find any instructions there or in docs site.
Both server will be behind the NAT with public IP.
When i try registration with registerServerTopology.sh there is a error:
{"code":500,"message":"Error from Central's register API : The platform: 'Remote-server'@'192.168.5.10' cannot be added to the Central linked to this Remote \/
Central's response => Code : No parent platform was found for : 'Remote-server'@'192.168.5.10'"}

I try to do that.
The central cannot connect to the remote, only the remote can connect to the central.
I can’t find a document to set it up.
I don’t understand how to add the remote server.
I add manually a remote server on the central.
I see a connection with “ss -plantu | grep 5556”
But the poller stay in not running.
Hello @ezohiko,
I assume you added the Remote Server by performing the following procedures:
Can you share with me your broker configuration on the Remote Server?
/etc/centreon-broker/*
You see a connection with “ss -plantu | grep 5556”, it means, gorgoned succeeds in establishing a tcp connection on port 5556.
The problem does not concern the gorgone process anymore.
If the poller stay in not running, it is perhaps because Centreon-Engine failed to establish a TCP connection on port 5669 of Central Server.
Then you could share with me the following logs
Central:
/var/log/centreon-broker/central-module-master.log
/var/log/centreon-broker/central-broker-master.log
Remote Server:
/var/log/centreon-broker/*
Check that centengine is started
Restart centengine, run this and send me the result:
grep cbmod /var/log/centreon-engine/centengine.log
Regards.
Hi,
i just want to ask if there is possible to connect remote server over internet(both site behind NAT),
with static public IP on both site. And how?

Something like this.
On central site should be redirect BBDO(TCP 5669) and HTTPS.
On remote server site should be redirected ZMQ(TCP 5556)
Remote server should only have his own poller.
Regards