moving into a vrf on a cisco device causes Netmiko to time out.

Hello, so I have a scenario where I need to check some configuration in the global table and then in another vrf, however when doing this by sending multiple commands to netmiko I get a time out.

relevant code:

def ios_connector(i,q,ios_cmds,print_lock,outfile):
    while True:
        ip = q.get()
        IOS = {
                'device_type': 'cisco_ios',
                'host': ip,
                'username': conf.USERNAME,
                'password': conf.PASSWORD,
                #'secret': conf.SECRET,
                }
        # attempt to establish SSH session and quit with appropriate error if not successful
        try:
            starttime_time = datetime.now()
            print('INFO: connecting to '+str(ip))
            net_connect = ConnectHandler(**IOS)
            # collect output
            connection = net_connect.find_prompt()
            res = []
            for cmd in ios_cmds:
                output = net_connect.send_command(cmd)
                res.append(output)
            with print_lock:
                if len(res) > 0:
                    outfile.write(connection + " has returned the following output:\n\n")
                    for line in res:
                        outfile.write(line)
                    outfile.write('\n\n===\n\n')
                else:
                    outfile.write(connection + "\nno matches\n\n===\n\n")

        except (AuthenticationException):
            print("ERROR: Authentication Failure to {}\n".format(ip))
            q.task_done()
        except (NetMikoTimeoutException):
            print("ERROR: Timed out while trying to connect to {}\n".format(ip))
            q.task_done()
        except Exception as e:
            print('ERROR: Connection refused by ' + ip +'\n' + e)
            q.task_done()
        except (OSError) as e:
            print('ERROR: OSError\n' + e)
            q.task_done()
        except (EOFError) as e:
            print('ERROR: EOF error\n' + e)
            q.task_done()
        finally:
            net_connect.disconnect()
            endtime = datetime.now()
            print('Total time: {}'.format(endtime - starttime_time))
            q.task_done()

from the debug it looks like it’s a problem with find_prompt() as the prompt changes to include the vrf name, however it still has the trailing # as you would expect.

debug:

DEBUG:paramiko.transport:starting thread (client mode): 0x3747ba30 DEBUG:paramiko.transport:Local version/idstring: SSH-2.0-paramiko_2.7.1 DEBUG:paramiko.transport:Remote version/idstring: SSH-2.0-Cisco-1.25 INFO:paramiko.transport:Connected (version 2.0, client -1.25) DEBUG:paramiko.transport:kex algos:[‘diffie-hellman-group-exchange-sha1’, ‘diffie-hellman-group14-sha1’] server key:[‘ssh-rsa’] client encrypt:[‘aes128-ctr’, ‘aes192-ctr’, ‘aes256-ctr’] server encrypt:[‘aes128-ctr’, ‘aes192-ctr’, ‘aes256-ctr’] client mac:[‘hmac-sha2-256’, ‘hmac-sha2-512’, ‘hmac-sha1’, ‘hmac-sha1-96’] server mac:[‘hmac-sha2-256’, ‘hmac-sha2-512’, ‘hmac-sha1’, ‘hmac-sha1-96’] client compress:[‘none’] server compress:[‘none’] client lang:[‘’] server lang:[‘’] kex follows?False DEBUG:paramiko.transport:Kex agreed: diffie-hellman-group-exchange-sha1 DEBUG:paramiko.transport:HostKey agreed: ssh-rsa DEBUG:paramiko.transport:Cipher agreed: aes128-ctr DEBUG:paramiko.transport:MAC agreed: hmac-sha2-256 DEBUG:paramiko.transport:Compression agreed: none DEBUG:paramiko.transport:Got server p (2048 bits) DEBUG:paramiko.transport:kex engine KexGex specified hash_algo <built-in function openssl_sha1> DEBUG:paramiko.transport:Switch to new keys … DEBUG:paramiko.transport:Adding ssh-rsa host key for redacted DEBUG:paramiko.transport:userauth is OK INFO:paramiko.transport:Authentication (password) successful! DEBUG:paramiko.transport:[chan 0] Max packet in: 32768 bytes DEBUG:paramiko.transport:[chan 0] Max packet out: 4096 bytes DEBUG:paramiko.transport:Secsh channel 0 opened. DEBUG:paramiko.transport:[chan 0] Sesch channel 0 request ok DEBUG:paramiko.transport:[chan 0] Sesch channel 0 request ok DEBUG:netmiko:read_channel: THIS DEVICE IS PART OF A

                    ------------------------



                         PRIVATE NETWORK

                         ---------------





         ************************************************

         * Unauthorised access or use of this equipment *

         *   is prohibited and constitutes an offence   *

         *     under the Computer Misuse Act 1990.      *

         *    If you are not authorised to use this     *

         *     system, terminate this session now.      *

         ************************************************

switch-01# DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:write_channel: b’\n’ DEBUG:netmiko:read_channel:

switch-01# DEBUG:netmiko:read_channel: DEBUG:netmiko:[find_prompt()]: prompt is switch-01# DEBUG:netmiko:read_channel: DEBUG:netmiko:In disable_paging DEBUG:netmiko:Command: terminal length 0

DEBUG:netmiko:write_channel: b’terminal length 0\n’ DEBUG:netmiko:Pattern is: terminal\ length\ 0 DEBUG:netmiko:_read_channel_expect read_data: t DEBUG:netmiko:_read_channel_expect read_data: erminal length 0

switch-01# DEBUG:netmiko:Pattern found: terminal\ length\ 0 terminal length 0

switch-01# DEBUG:netmiko:terminal length 0

switch-01# DEBUG:netmiko:Exiting disable_paging DEBUG:netmiko:write_channel: b’terminal width 511\n’ DEBUG:netmiko:Pattern is: terminal\ width\ 511 DEBUG:netmiko:_read_channel_expect read_data: t DEBUG:netmiko:_read_channel_expect read_data: erminal width 511

switch-01# DEBUG:netmiko:Pattern found: terminal\ width\ 511 terminal width 511

switch-01# DEBUG:netmiko:read_channel: DEBUG:netmiko:read_channel: DEBUG:netmiko:write_channel: b’\n’ DEBUG:netmiko:read_channel:

switch-01# DEBUG:netmiko:read_channel: DEBUG:netmiko:[find_prompt()]: prompt is switch-01# DEBUG:netmiko:read_channel: DEBUG:netmiko:write_channel: b’\n’ DEBUG:netmiko:read_channel:

switch-01# DEBUG:netmiko:read_channel: DEBUG:netmiko:[find_prompt()]: prompt is switch-01# DEBUG:netmiko:read_channel: DEBUG:netmiko:write_channel: b’routing-context vrf vnName\n’ DEBUG:netmiko:Pattern is: routing-context\ vrf\ vnName DEBUG:netmiko:_read_channel_expect read_data: r DEBUG:netmiko:_read_channel_expect read_data: outing-context vrf vnName

switch-01%vnTrust# DEBUG:netmiko:Pattern found: routing-context\ vrf\ vnName routing-context vrf vnName

switch-01%vnTrust# DEBUG:netmiko:read_channel:

[repeated a lot]

DEBUG:netmiko:read_channel: DEBUG:netmiko:write_channel: b’\n’ DEBUG:netmiko:Pattern is: # DEBUG:netmiko:_read_channel_expect read_data:

switch-01%vnName# DEBUG:netmiko:Pattern found: #

switch-01%vnName# DEBUG:netmiko:exit_config_mode: DEBUG:netmiko:write_channel: b’exit\n’ DEBUG:paramiko.transport:EOF in transport thread

[llama85]

@ktbyers works like a charm! thank you.

[ktbyers]

@leearmitage I would try to execute the following:

            for cmd in ios_cmds:
                output = net_connect.send_command(cmd, expect_string=r"#")
            net_connect.set_base_prompt()

So here I use the expect_string argument so it doesn’t care about the prompt changing (this should allow both commands to be executed).

I then reset the base_prompt after the for-loop is done. In general, you probably need to execute that set_base_prompt() anytime the prompt fundamentally changes like that.

Let me know if that works (or not).