Python Scripts Examples - Reboot/Manage/Monitor Network Devices

Basically I am creating a script to build SSH connection from my Windows 7 network management computer to Cisco devices and have interactive commands with those Cisco devices. This has been done by many other network engineer. With Google's help, I am able to get their experiences to quickly implement it in my home lab environment.

It will be part of network management automation task. If
I can get this working it will prevent me from having to sign on to all of my Cisco devices and issue the command manually. Previously I used  network automation tool InfoBlox NetMRI to achieve that. Now with Python script, it can be achieved almost with a very low cost.

Step 1. Install Python and necessary components on my Windows 7 Machine.
I had a post before to describe the steps how to install Python and related module into windows system.

• Install Python 2.7.15
• Download and install pycrypto win-amd64-py2.7.exe
• Open a command prompt window. Change the path to c:\Python27 then  and go to Scripts directory.
• pip install paramiko

• Test with the following command:
• import paramiko

Step 2. Create a Script

C:\Python27>type cisco.py

import paramiko
from getpass import getpass
import time
import datetime
import sys

ip = "192.168.2.5"
username = "Cisco"
password = "Cisco"

f = open('1Reboot-APlog.txt', 'a')
old_stdout = sys.stdout
sys.stdout = f
remote_conn_pre=paramiko.SSHClient()
remote_conn_pre.set_missing_host_key_policy(paramiko.AutoAddPolicy())
remote_conn_pre.connect(ip, port=22, username=username,  
                        password=password,
                        look_for_keys=False, allow_agent=False)

remote_conn = remote_conn_pre.invoke_shell()
output = remote_conn.recv(65535)
print('\n\n\n##############################################################\n')
print (datetime.datetime.now())
print('\n##############################################################\n')
print (output)

remote_conn.send("enable\n")
time.sleep(.5)
output = remote_conn.recv(65535)
print (output)

remote_conn.send("Cisco\n")
time.sleep(.5)
output = remote_conn.recv(65535)
print (output)

remote_conn.send("reload\n")
time.sleep(.5)
output = remote_conn.recv(65535)
print (output)


remote_conn.send("y\n")
time.sleep(.5)
output = remote_conn.recv(65535)
print (output)

C:\Python27>python cisco.py

C:\Python27>type Newdaytest.txt
##############################################################
2018-08-24 12:38:42.178000
##############################################################

****************************************************************
* This is a private computing facility.                        *
* Unauthorized use of this device is strictly prohibited.      *
* Violators will be prosecuted to the maximum extent possible. *
*                                                              *
* TACACS+ Authentication and Accounting are in place.          *
* All actions/commands are monitored and recorded.             *
* By using the network you expressly consent to such           *
* monitoring and recording.                                    *
****************************************************************

SW-FW-MGMT1#config t
Enter configuration commands, one per line.  End with CNTL/Z.
SW-FW-MGMT1(config)#
file prompt quiet
SW-FW-MGMT1(config)#
end
SW-FW-MGMT1#
copy running-config tftp://192.168.154.5/
.
.
.

3. Schedule Daily Reboot Task in Windows 

Create a new daily task to run following command:

c:\Python27\python.exe c:\Python27\1reboot-ap.py

4. Check Logs
Check log file 1Reboot-APlog.txt created under c:\Python27
##############################################################
2018-08-24 15:06:29.151000
##############################################################


1142>
enable
Password: 

1142#
reload
Proceed with reload? [confirm]

5. Examples: Monitor Remote Network Port 

C:\Python27>type telnet_monito.py

# -*- coding: utf-8 -*
import telnetlib,time,os

Path = os.getcwd()
file_name = 'telnet_mon_log.txt'
telnet_mon_log_path = os.path.join(Path,file_name)

if not os.path.exists(telnet_mon_log_path):
    os.mknod(file_name)

while True:
    try:
        tn=telnetlib.Telnet('10.94.200.4',80)
    except Exception as e:
        with open(telnet_mon_log_path,'a',encoding='utf-8') as f:
            f.write(time.strftime("%b %d %Y %H:%M:%S", time.localtime()) + 'Network Abnormal\n')
    else:
        continue

    time.sleep(1)