sshconfig

Host github.com
    HostName github.com
    AddKeysToAgent yes
    UseKeychain yes
    User git
    IdentityFile ~/.ssh/personal
    IdentitiesOnly yes

Host gitlab.cern.ch
    HostName gitlab.cern.ch
    User git
    Port 7999
    IdentityFile ~/.ssh/cern

Host *.cern.ch !lxplus.cern.ch !ciadm.cern.ch !ciadm !aitnadm.cern.ch !aiadm.cern.ch !lxplus !aiadm !aitnadm !gitlab.cern.ch !ciadm !ciadm.cern.ch
    User chbarnes
    ProxyJump lxplus.cern.ch
    PreferredAuthentications gssapi-with-mic,keyboard-interactive,password
    GSSAPIDelegateCredentials yes
    GSSAPIAuthentication yes
    IdentitiesOnly yes
    ServerAliveInterval 30

Host ciadm.cern.ch ciadm lxtunnel.cern.ch lxplus.cern.ch aiadm.cern.ch lxtunnel lxplus aiadm
    User chbarnes
    # if your client is configured for Kerberos
    GSSAPIDelegateCredentials yes
    GSSAPIAuthentication yes
    # SOCKS5 proxy for web, see below
    DynamicForward 8090
    ExitOnForwardFailure no

# Some specifics for if logging in as root or user
Match Host *.cern.ch User root
    # Don't forward my personal krb tickets when logging in as root.
    GSSAPIDelegateCredentials no
    ForwardAgent no
    PubkeyAuthentication yes