Linux
Archssh
To fix:
Unable to negotiate with x.x.x.x port 22: no matching key exchange method found. Their offer: diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
Add to ssh command:
oKexAlgorithms=+diffie-hellman-group1-sha1
Or permanently add to .ssh/config
Host 123.123.123.123
KexAlgorithms +diffie-hellman-group1-sha1
From: https://unix.stackexchange.com/questions/340844/how-to-enable-diffie-hellman-group1-sha1-key-exchange-on-debian-8-0/340853