No matching key exchange method found

Ran into this again while trying to ssh into the old battleship:

no matching key exchange method found. Their offer: diffie-hellman-group1-sha1

A solution is to specify the key exchange algorithm on the command line:

ssh -o KexAlgorithms=+diffie-hellman-group1-sha1 root@169.254.8.70

More information can be found on OpenSSH's Legacy Options page.