Unable to negotiate with port 22: no matching key exchange method found.

Working with an older Cisco ASA, I was not able to directly SSH to the host using SSH on Windows unless I specified the diffie-hellman-group1-sha1 algorithm.

PuTTY gives the following warning:

For Windows, I can use the following command to SSH (as well as SCP).

ssh -oKexAlgorithms=+diffie-hellman-group1-sha1 user@host