For "older" EXOS switches, I added an alias to my bash_profile (OS to automatically add the older cypher. That way the extra algorithms are added by using:
code:oldssh (switch_address)
Here's what I added:
$ grep oldssh .bash_profile
alias oldssh='ssh -o KexAlgorithms=+diffie-hellman-group1-sha1 -o HostKeyAlgorithms=+ssh-dss'