With Ubuntu 15.10 and before, I had a host entry with "Protocol 1" in my .ssh/config file.
Ubuntu 16.04 doesn't have support for SSH1 anymore per default.
corben@ubuntu1604:~$ ssh -1 host ssh1 is not supported
When using the ssh client with any host entry having a "Protocol 1" line in .ssh/config it complains with:
corben@ubuntu1604:~$ ssh host .ssh/config line <nr>: Bad protocol spec '1'.
To connect to my host using ssh1, I could install the package openssh-client-ssh1 and call ssh1 instead of ssh . But the ssh1 client doesn't use the host entry configured in .ssh/config, when the "Protocol 1" line is omitted. There is no man page for ssh1 and "man ssh" still lists the -1 option for protocol version 1. I want to use a host entry as I have port forwarding and ssh keys configured, which I don't want to enter each time on the command line.
How to use ssh and ssh1 in coexistence and .ssh/config?
The host is an embedded device still in service, where no firmware updates will be released. As it is used in a LAN environment the security aspect using ssh version 1 isn't an issue.