Host bastion
    User dzahn
    HostName bast3004.wikimedia.org
    IdentityFile /home/mutante/ssh/wikimedia.org-prod-ed25519-dzahn-2019
    ForwardAgent no
    IdentitiesOnly yes 

Host *.wmnet
    User dzahn
    ProxyCommand ssh -W %h:%p bastion
    IdentityFile /home/mutante/ssh/wikimedia.org-prod-ed25519-dzahn-2019
    ForwardAgent no
    IdentitiesOnly yes