Python script to change/update hostname's of multiple Cisco devices.

[shivshankarjalanila]

Hi,

It will be very helpful if someone can help with a script (preferably Python) using which I can change/update the hostnames of multiple Cisco devices instead of doing it one by one manually.

I already have the hostname configured just need to update the hostname across 100s of Cisco devices to maintain the standards.

Please note, I am very new to automation and for now, I only know how to SSH into Cisco devices using Python+Netmiko.

Thank you

Shiv

[inderdeeps]

@shivshankarjalanila : Check if it helps 

https://thwack.solarwinds.com/product-forums/network-configuration-manager-ncm/f/forum/55733/hostname-change-in-multiple-cisco-devices 

[shivshankarjalanila]

Hi @inderdeeps, Thank you for your response. I am looking for something simple to understand.

[balaji.bandi · Accepted solution]

Here is Pythion script easy to understand and simple to replace what you like to replace on the devices :

https://github.com/grelleum/youtube-network-automation

check the youtube, his series simple, in hours time you can do what you want.

[shivshankarjalanila]

Hi @balaji.bandi, Thank you for your response.

I went through few initial videos. It seems simple and interesting. Let me go through all and see if I find the solution.

Thank you

Shiv 

[balaji.bandi]

if you see all 9 or 10 videos, you become python network programmer can do day to day task.

Good Luck.

[Seb Rupik · Accepted solution]

Hi there,

Try the following:

#!/usr/bin/env python3
import getpass
import csv
import netmiko
import paramiko
from argparse import ArgumentParser


def main():
    parser = ArgumentParser(description='Arguments for running oneLiner.py')
    parser.add_argument('-c', '--csv', required=True, action='store', help='Location of CSV file')
    args = parser.parse_args()

    ssh_username = input("SSH username: ")
    ssh_password = getpass.getpass('SSH Password: ')

    with open(args.csv, "r") as file:
        reader = csv.DictReader(file)
        for device_row in reader:
            try:
                ssh_session = netmiko.ConnectHandler(device_type='cisco_ios', ip=device_row['device_ip'],
                                                     username=ssh_username, password=ssh_password)

                print("+++++ {0} +++++".format(device_row['device_ip']))
                commands = ["hostname {0}".format(device_row['new_hostname'])]
                ssh_session.enable()
                ssh_session.send_config_set(commands)
                ssh_session.send_command("wr mem")
                ssh_session.disconnect()

            except (netmiko.ssh_exception.NetMikoTimeoutException,
                    netmiko.ssh_exception.NetMikoAuthenticationException,
                    paramiko.ssh_exception.SSHException) as s_error:
                print(s_error)


if __name__ == "__main__":
    main()

You will need to feed it a csv file with the following format:

device_ip,new_hostname
192.168.1.1,new_host01
192.168.1.2,new_host02
192.168.1.3,new_host03

# python3 -c new_hostnames.csv

The script will prompt you for a username and password and will use those credentials for every device in the csv file.

cheers,

Seb.

[shivshankarjalanila · Accepted solution]

Hi There,

Thank you everyone for the help and pointers.

I completed the task using the script and prerequisite points mentioned below.

1. I ran Python on a Windows laptop.

2. Used a SwitchIPList.txt file.

3. I used the below script.

Task accomplished.

I have added a lot of separators, you can edit/remove them.

Below is the script that executed repetitive commands on multiple network nodes. I hope it helps.

from netmiko import ConnectHandler
from getpass import getpass
#import sys

#SSH to multpile devices
#create device template
with open("SwitchIPList.txt") as switches:
    for IP in switches:
        Switch = {
            "device_type": "cisco_ios",
            "ip": IP,
            "username": input("Username: "),
            "password": getpass(),
#            "username": "",
#            "password": "",
        }
        net_connect = ConnectHandler(**Switch)
############################## Connect to IP ##############################
        print("*"*90)
        print ("Connecting to " + IP)
        print("*"*90)
############################## show commands ##############################
        output = net_connect.send_command("show run | s aaa group|radius server")
        print(output)
        print("-"*72)
############################## Config radius server ##############################
        config_commands = ["radius server naca001.nac.com\n",
                            "address ipv4 10.200.0.1 auth-port 1812 acct-port 1813\n",
                            "automate-tester username GNSRADIUS idle-time 10\n",
                            "key YourPassword\n",
                            "!\n",
                            "radius server naca002.nac.com\n",
                            "address ipv4 10.200.0.2 auth-port 1812 acct-port 1813\n",
                            "automate-tester username GNSRADIUS idle-time 10\n",
                            "key YourPassword\n",
                            "!\n",
                                                        	]
        output = net_connect.send_config_set(config_commands)
        print(output)
        print("-"*72)
        output = net_connect.send_command("show run | s aaa group|radius server")
        print(output)
        print("-"*72)
############################## Test NAC ##############################
        print("+"*10,"Test to radius server naca001.nac.com - 10.200.0.1","+"*10)
        output = net_connect.send_command("test aaa group NAC-V2 test test legacy")
        print(output)
        print("-"*72)
        output = net_connect.send_command("wr")
        print(output)
        print("-"*72)
        print("="*27,"END OF SWITCH","="*27)
        
#Close the connection
net_connect.disconnect()

Thank you

Shiv