I would like to connect my IRC server to the hackint network so all chats and channels that are hold on my IRC server are also mirrored in the hackint.net.
How can I set up that connection?
I am a bit unlucky in searching for it, cause I seem not to find the right keywords (peering???)
On
IRCD-Hybrid -- High Performance Internet Relay Chat:
apt-get install ircd-hybrid
Then you have to adapt the configuration file to Connect Multiple IRC Servers
In the IRC world it's called "linking a server"
On
You don't automatically connect your ircd to a big irc network.
A big irc network has linking procedures and doesnt accept links from just anyone. You need to join the queue along with many others who want the same, you have to build trust and friendships with other server administrators and above all you must be altrustic and not want to just become an irc operator/admin.
Did you know that a lot of big irc servers (e.g. on efnet, freenode etc) are donated for free by businesses etc, and the donators don't even have any access beyond that of a user?
You may want to read on the linking policies of big networks to get an idea of the requirements, they expect servers with some level of performance, resilience to DDoS, good routing, and not a simple VPS:
https://www.dal.net/?page=Application%20Guidelines
You can use a bit of another Concept:
set up a Matrix synapse node and an IRC-Bridge
All chats and users will be stored locally in your homeserver and whenever possible mirrored in the IRC-Chat and back.
This is what I ended up with, so I'll set this as accepted answer, although the other hints are good to know and also valid.