I am unable to ssh to a server that asks for a diffie-hellman-group1-sha1 key exchange method:ssh 123.123.123.123Unable to negotiate with 123.123.123.123 port 22: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1How to enable the diffie-hellman-group1-sha1 key exchange method on Debian 8.0?I have tried (as proposed here) to add the following lines to my /etc/ssh/ssh_configKexAlgorithms diffie-hellman-group1-sha1,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1Ciphers 3des-cbc,blowfish-cbc,aes128-cbc,aes128-ctr,aes256-ctrregenerate keys with ssh-keygen -Arestart ssh with service ssh restartbut still get the error.
How to enable diffie-hellman-group1-sha1 key exchange on Debian 8.0?
debian;ssh;openssh;key authentication;ssh agent
The OpenSSH website has a page dedicated to legacy issues such as this one. It suggests the following approach:ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 123.123.123.123or more permanently, addingHost 123.123.123.123    KexAlgorithms +diffie-hellman-group1-sha1to ~/.ssh/config.