The main tilde.club IRC server needs to allow traffic from the remote server; this means that we need to allow traffic from the specific IP address to either port `6667` (for non-SSL connections) or port `6697` (for SSL connections).
There needs to be [a `connect` section](https://github.com/tildeclub/tilde.club/blob/master/docs/ircserver.md#connect-section) in the `ircd.conf` file for each remote server. See [the documentation for our server setup](https://github.com/tildeclub/tilde.club/blob/master/docs/ircserver.md#connect-section) for full information about how this is configured.
You should have the `/var/log/charybdis/serverinfo` log file enabled, and it's this file that will contain the pertinent information about the success or failure of server connections.