Paramiko "Unknown Server"

Question

I'm trying to get started with the Paramiko library, but the library is throwing an exception as soon as I try to connect with the following simple program:

import paramiko ssh = paramiko.SSHClient() ssh.connect('127.0.0.1', username='boatzart', password='mypassword') 

The error I get is:

Traceback (most recent call last): File "test.py", line 6, in <module> ssh.connect('127.0.0.1') File "build/bdist.macosx-10.7-intel/egg/paramiko/client.py", line 316, in connect File "build/bdist.macosx-10.7-intel/egg/paramiko/client.py", line 85, in missing_host_key paramiko.SSHException: Unknown server 127.0.0.1 

This occurs no matter which server I try.

Answer 1

I experienced the same issue and here's the solution that worked out for me:

import paramiko  client = paramiko.SSHClient() client.set_missing_host_key_policy(paramiko.AutoAddPolicy()) client.connect('127.0.0.1', username=username, password=password) stdin, stdout, stderr = client.exec_command('ls -l') 

This is to set the policy to use when connecting to a server that doesn't have a host key in either the system or local HostKeys objects. The default policy is to reject all unknown servers (using RejectPolicy). You may substitute AutoAddPolicy or write your own policy class.

More details at paramiko api doc. Hope this helps.

After that you can save into an other keyfile file for next usage as follows.

ssh.get_host_keys().save('/some/file/path') 

You can always load from a file as follows.

ssh.load_host_keys('/some/file/path') 

Answer 2

The exception was raised because you are missing a host key, the rather cryptic "Unknown server" is the clue - since the exception was raised from missing_host_key

Try this instead:

import paramiko  paramiko.util.log_to_file('ssh.log') # sets up logging  client = paramiko.SSHClient() client.load_system_host_keys() client.connect('127.0.0.1', username=username, password=password) stdin, stdout, stderr = client.exec_command('ls -l')