IOError: Search pattern never detected in send_command_expect

Hi,

I am using netmiko and python to collect CPU information from Cisco IOS based access points. In most instances the script works fine, but on other occasions it fails and I cannot determine why.

python version = 2.7.8 netmiko version = 1.0.0 paramiko version = 2.0.2

Code sample:

            if icmp_response == 0:
                try:
                    device = ConnectHandler(device_type='cisco_ios', ip=APIPAddr, username=Aplogin, password=ApPassword)
                    sleep(0.5)
                    output = (device.send_command('show proc cpu | include LWAPP CLIENT')).encode("utf-8").split()
                    sleep(0.5)
                    device.disconnect()
                    logging.info('CPU usage for %s (%s) @ %s' % (DeviceName, DeviceIP, output[5].strip('%')))
                except NetMikoTimeoutException:
                    logging.info('SSH connection failed to %s (%s)' % (DeviceName, DeviceIP))
                except NetMikoAuthenticationException:
                    logging.info('AP Authentication Failure for %s (%s)' % (DeviceName, DeviceIP))
                except Exception:
                    logging.exception('Exception for %s (%s)' % (DeviceName, DeviceIP))
                    logging.info('Exception ...', output)
            else:
                logging.info('Device not pingable for %s, %s' % (DeviceName, DeviceIP))

Log Message:

Sat, 08 Oct 2016 12:36:01 CPU usage for ap2602 (10.36.14.152) @ ['81', '51008', '1355556', '37', '0.00%', '0.00%', '0.00%', '0', 'LWAPP', 'CLIENT']
Sat, 08 Oct 2016 12:36:01 CPU usage for ap2602 (10.36.14.152) @ 0.00
Sat, 08 Oct 2016 12:36:09 CPU usage for ap2602 (10.36.190.159) @ ['81', '26408', '915727', '28', '0.00%', '0.00%', '0.00%', '0', 'LWAPP', 'CLIENT']
Sat, 08 Oct 2016 12:36:09 CPU usage for ap2602 (10.36.190.159) @ 0.00

Error Message:

Sat, 08 Oct 2016 12:38:00 Exception for ap2602 (10.x.x.x)
Traceback (most recent call last):
  File "/home/user1/CheckCPU.py", line 430, in CPUQuery
    output = (device.send_command('show proc cpu sort | inc LWAPP CLIENT')).encode("utf-8").split()
  File "/home/user1/venv/lib/python2.7/site-packages/netmiko/base_connection.py", line 645, in send_command
    search_pattern))
IOError: Search pattern never detected in send_command_expect: 51

Sat, 08 Oct 2016 12:38:00 *** CPUQuery() Error ***
Traceback (most recent call last):
  File "/home/user1/CheckCPU.py", line 443, in CPUQuery
    logging.info('Exception ...', output)
UnboundLocalError: local variable 'output' referenced before assignment

Manual Test:

[user1@hj1 ~]$ ssh -l admin 10.x.x.x
The authenticity of host '10.x.x.x (10.x.x.x)' can't be established.
RSA key fingerprint is 6b:c5:79:6e:13:f5:00:00:00:00:bb:08:99:5a:0d:b4.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '10.x.x.x' (RSA) to the list of known hosts.
Password: 
ap2602>show proc cpu | include LWAPP CLIENT
  81       35028      870017         40  0.00%  0.00%  0.00%   0 LWAPP CLIENT     
ap2602>quit
Connection to 10.x.x.x closed.

[ktbyers]

@zeepi222 Okay, wrong format. It is an attribute (not a method) so no parenthesis.

print(device.base_prompt)

Try the following and let me know if it works:

time.sleep(3)
device.clear_buffer()
output = (device.send_command('show processes cpu | include CPU', expect_string='ap2602>')).encode("utf-8").split()

The send_command_expect() method tries to determine the routers prompt and use this as a trailing pattern for determining command completion. This looks like it is failing (possibly due to the router being slow).

This will only work for that one particular device, but I want to see if it fixes your problem.

[carrascodc]

I wrote a script that worked with Cisco NXOS and IOS, and then I tried to apply it to the F5 LTM and hit this error. The solution mentioned by zeepi222 fixed this problem. Thank you !!!

net_connect = ConnectHandler(**Node) time.sleep(2) <<< Resolved this error message print(net_connect.find_prompt()) print(net_connect.send_command(‘modify security firewall address-list EXT-Test addresses add {1.1.1.1}’) print(net_connect.send_command(‘modify security firewall address-list EXT-Test addresses add {4.4.4.4}’)