First rake. ShellGuard, my beloved ShellGuard - won’t connect. sshd is running and configured, I can log in locally on 127.0.0.1. Even PuTTY connected. Though sluggishly. But ShellGuard says

no matching comp found. Client zlib Server: none,zlib@openssh.com

Thanks to opennet. Turns out the fix is

"Compression yes" in /etc/ssh/sshd_config

and also

PasswordAuthentication yes

Though it connected sluggishly too. I’m blaming the huge number of interfaces and a running torrent. If it’s this slow on a real machine (up to 30 seconds to log in), the question will come up again.