SSH fails on second time

[synergiator]

How is it possible that if you create two ssh connections one after another, the second fails? login works otherwise if tested manually.

def do_ssh_login(self, ip, password, port = 22):
        host = "cloud@"+ip+":"+ str(port)
        print("try login to host: %s with password %s" % (host, password))
        try:
            Connection(host=host )
            c = Connection(host = host, connect_kwargs={"password": password})
            result = c.run('uname -a')
            c.close()
            print(result)

First time to one host this function works; second time to another host there is this error:

Error opening None: Unable to connect to port 22 on <IP>