If you cannot connect to a server over the network...
One of two things can be happening:
(a) If you accidentally used an incorrect SSH username to connect, our intrusion detection system has blocked your address for up to 10 minutes. If you don't want to wait that long, create a help desk ticket, including your SSH username and destination machine's address.
(b) If your server is using an IP address whitelist, please check your current IP address via an external resource such as this one, then create a help desk ticket, including your current IP address and destination machine's address.
If you can connect over the network but are receiving an SSH error...
If you see an error message such as "permission denied (publickey)" when attempting to SSH or deploy via git push, it suggests an authentication issue related to an invalid or missing SSH key.
Be sure the key you are using matches the key deployed to your server. The default SSH key path on your local machine is likely ~/.ssh/id_rsa (Linux / Mac). But if you provided us with a different key than the default, you will need to either specify that key when connecting or load it into an SSH agent session.
For example, to point to a different key path:
ssh firstname.lastname@example.org -i ~/.ssh/id_some_other_key
(Be sure you set username and server-id to your actual environment values)
Or to load the key into your SSH agent:
eval "$(ssh-agent -s)" ssh-add ~/.ssh/id_some_other_key
If you are using Windows for your local development environment, we highly recommend using Git Bash as part of the free Git for Windows package instead of PuTTY for all SSH connections and git-based deployments. The advantage of using Git Bash is it provides a simple interface consistent with Linux interfaces and is much easier to manage than PuTTY.
If your environment has Dokku installed, you can run the following command to debug your SSH connection:
ssh -vvvv email@example.com
If your key matches up, you will see a bunch of debug output and then a list of Dokku commands.
If you're stuck, feel free to open a support ticket, and we'll do our best to help you out.