The two available client types, default native clients based on ssh2-python (libssh2) and clients under pssh.clients.ssh based on ssh-python (libssh) support different authentication mechanisms and features.
Below is a comparison of feature support for the two client types.
| Feature | ssh2-python (libssh2) | ssh-python (libssh) |
|---|---|---|
| Agent forwarding | No | Not yet implemented |
| Proxying/tunneling | Yes | No |
| Kerberos (GSS) authentication | Not supported | Yes |
| Private key file authentication | Yes | Yes |
| Agent authentication | Yes | Yes |
| Password authentication | Yes | Yes |
| OpenSSH config parsing | Not yet implemented | Not yet implemented |
| ECDSA keys support | Yes | Yes |
| ED25519 keys support | Yes | Yes |
| Certificate authentication | Not supported | Yes |
| SFTP copy to/from hosts | Yes | No |
| SCP functionality | Yes | No |
| Keep-alive functionality | Yes | No |
The default client offers the most features, but lacks certain authentication mechanisms like GSS-API and certificate authentication. Both client types are based on C libraries and offer similar levels of performance.
Users that need the authentication mechanisms not supported by the default client can from pssh.clients.ssh import ParallelSSHClient, SSHClient instead of the default clients.