ssh delay when connecting
We have a CentOS server that we use for internal testing purposes, which has sshd enabled.
When I (as a developer) am at the company, I use
ssh email@example.com to connect to it - and it works flawlessly.
Now, in order to work from home, accessing the server via the company's static IP, we set up another port for ssh, 2020. So I execute
ssh -p 2020 firstname.lastname@example.org and am immediately granted for a password. After entering the password, it takes up to 30 seconds until I can access the server. Same is with SFTP (i.e. uploading files takes about 30 seconds until it begins to transfer). As you can imagine, if you have to regularly upload files to a webserver via SFTP, this is very tedious.
So I looked at similar questions and thus edited the sshd_config file on the server, setting UseDNS to "no" and GSSAPIAuthentication to "no" (this one also in ssh_config on the client) - it did not work..
Please have a look at the -vvv output when externally accessing the server:
ssh -p 2020 -vvv email@example.com
What could it be? Do you need more info?