Using Roumenpetrov‘s “PKIX-SSH” SSH Client for Logging

To use the user-certificate for logging into the ExtremeXOS SSH server, you need to concatenate the key file and certificate file as a single file, and also ensure that the file does not have a very open permission level (that is, accessible by others).
$ cat exos-admin-key.pem exos-admin-cert.crt > exosadmincert.crt
$ chmod 0600 exosadmincert.crt

$ ssh -i exosadmincert.crt exos-admin@

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DUT1_switch_model.1 # show session
    #       Login Time               User     Type    Auth   Auth Location
*7          Thu Oct 20 20:25:37 2016 exos- .. ssh2    x509v3 dis

DUT1_switch_model.2 # show session detail

ID                  :7
Start Time          :Thu Oct 20 20:25:37 2016
User Name           :exos-admin
Type                :ssh2
Authentication      :x509v3
Cli Authentication  :disabled
Location            :
Node                :local

DUT1_switch_model.3 # sh log
10/20/2016 20:25:37.17 <Info:AAA.LogSsh> Msg from Master : Did x509v3 authentication for user exos-admin (
10/20/2016 20:25:37.17 <Info:AAA.LogSsh> Msg from Master : Login passed for user exos-admin through ssh (