GNS3 Talks: Python for Network Engineers with GNS3 (Part 1). Network programmability made easy.

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Learn Python programming with GNS3. In this series of videos I will show you how you can quickly and easily program Cisco networks using Python. In this video we program a Cisco IOSv router using Python on an Ubuntu Docker container.
The script used in this video is available on GitHub here:
github.com/davidbombal/python...
Transcription:
This is one of multiple videos discussing Python programming. Now there's a lot of information on the internet with regards to Python programming, but in these series of videos I'm going to concentrate solely on the use of Python with networking devices and specifically with gns3 .
I'm a very strong believer in practical learning. Think about it, when you were a child, did you go to university or school to learn how to ride a bike? Typically you learnt how to ride a bike by riding a bike and falling off a few times, making mistakes. But as you practiced you got better and better at riding a bike.
I think the same is true for any other skill that you want to gain and any other knowledge that you want to obtain. The best way to do it is to just do it , make mistakes, pick yourself up and try again. And with that in mind I'm going to show you how quickly you can get programming a Cisco network using Python.
In Google I've done a search for Python telnet and my first hitch is the telnet library or telnet client available in Python 2.7. Now there's a large debate in Python community about which version of Python you should learn. Python 2.7 is being replaced by Python 3. But notice on the Python website you can still download Python 2.7 and a lot of operating systems and network devices have version 2.7 by default. I'm going to show you both Python 2.7 and python 3 as part of these videos or as part of my GNS3 Python course. You may only have Python 2.7 available so it's good to know that but you should also learn Python 3 for the future.
So notice the simple script that we can copy from the Python documentation. We'll start off with a script and start programming our GNS3 topology.
In GNS3, I'm going to drag a iOS router to the workspace as well as an iOSv switch. These devices take a while to boot up, so to allow my docker containers to connect to the Internet quickly, I'm going to use a layer 2 switch. One of the docker containers available is in a blue 2 container and that's what I'm going to use in this topology rather than trying to get python running on your Windows PC or trying to get Python working on other operating systems. It's going to be a lot quicker for us just to use a docker container and add that to our GNS3 topology.
Again, my belief is start or learning as quickly as you can, make mistakes and learn from that. Don't get hung up with trying to learn the best way to do everything right away. Just get started.
Some people believe that they need to have a degree to become a programmer or use programming skills in networking. I don't necessarily agree with that. Just get started.
So on the Ubuntu machine I'm going to edit to the config. I'm going to set this device to use DHCP and click Save and click start. To boot up the network, I'm going to open up a console
to each device.
Now again the Cisco devices will take a while to boot up but our docker container has already booted up and we can already ping google.com even though the switch and the router are still
booting.
So how to get update? We will get update our references in ubuntu, that's done, will install Python.
In this first example I'm going to install Python 2.7. So Python version of Python that we're using is 2.7. 1. So here is the script that we're going to start off with it's not perfect. What we will be doing now is not necessarily the most optimized way of implementing a script like this but the
idea there is, we want to get started, get it working by for instance creating a loop back on the router and configuring VLANs on the switch and then we can build on our script and optimize it.
I'm going to use nano to create a file so let's call this python Router1 script 1 to start off with. And then I'm going to paste the code off the internet into nano. so we’re importing modules here get passes telnet library.
The device that we're going to telnet to is going to be the router. So we need to configure the router's IP address, username and password and other details for when the script telnets
to the router. So before we continue with our script let's configure the network devices. See here's the router it's booted up. Now I'll bypass the initial configuration dialog.
Transcription limited by KZbin.

[@alreid12345]

Lovin this Python content and look forward to more. When will the Python specific course be available?. Hopefully not too expensive but whatever it is "shut up and take my money!!!" Thank you once again.

[@davidbombal]

Al, thank you for the comments! Great to get feedback like this :) I hope to get initial versions of the Linux and Python courses out in the next few weeks. I' ll probably release a starter versions so people can access content quicker and then continue to add content to them like I do with the KZbin videos. Thoughts?

[@alreid12345]

David Bombal sure sounds like a solid plan. please let the channel know where this can be purchased and hopefully it will be on Udemy and GNS3 Academy. Are you going to cover things like Netmiko and NAPLAM?. I would also love to see an Ansible series and would also pay for good useful practical training on Ansible. Thank you and I'm also running through your CCNA Voice series at the moment and really enjoying that content but for very different reasons. Thanks again.

[@abdulravoofka363]

Looking forward in youtube as well as GNS3 academy...more and more. Very soon , i would like to start network programming using python scripts configuring different types network topologies...

[@davidbombal]

I will cover both Netmiko and NAPLAM and more. Initially I'll cover the basics and then get deeper and deeper. Ansible will be a separate course, but that is also on my list to create asap.

[@davidbombal]

Thank you! Lots of videos coming ...

[@mohammedelharfaoui]

Simply the best introduction to Network programming with Python. Thanks a lot.

[@albertlee8537]

Thanks David for sharing your knowledge! I also love “practical learning” especially via KZbin. This series that you have posted is an excellent way to have a feel of “networking programming”. Keep up the good work!

[@davidbombal]

Thank you Albert! I'm glad to hear you are enjoying the videos :)

[@bernardbain5302]

Love theses videos very clear and easy to understand unlike the constant issues you get with GNS3, I am constantly being bogged down with new issues which take days sometimes weeks to resolve totally hindering and slowing down the studying and learning process for me

[@Tcpipx]

Simply WOW! I recently discovered David's courses. I have to say, I finally see the light! This video was EXCELLENT! Is the first time I see Python applied to networking hands on! Thank you for that David!!!

[@davidbombal]

Thanks Robert! Glad to hear you are enjoying the videos :)

[@James67851]

It took me about a week to Learn GNS3 and get all of this to work through trial and error. I learned so much along the way about dockers, dynamits, virl, getting DHCP to work in for ubuntu, linux commands, Nano and alot more. I didn't know what any of the was when I started and today I was able to get this python script to work in my GNS3 environment. Thanks a lot this has shown me that I do have what it takes to further my IT career. Just start is a great motto. Thanks

[@LesterCarrejo]

David, I finally got around to trying this on a actual Cisco 3560 switch and IT WORKED Flawlessly!! Thank You for all of your informational video and especially the blogs with the DEV NET OPS, I hope it doesn't take me as long to try those out. Thanks again. You Rock!!

[@davidbombal]

Thank you! And well done!

[@MrDropvis]

Thank you for sharing this knowledge, been a fan of your video's for a while and wanted to thank you as your video's are awsome !! keep the good work

[@rougearlequin]

Best intro to Python for Network so far. Keep up the good work!

[@davidbombal]

Thank you. Stay tuned!

[@TravelisToLive]

Hey David! you are doing a good job man, keep up the spirit. This is going to help a lot of network engineers across the globe. Love from INDIA

[@kebeeyong9360]

Finally i'm up and running with GNS 3 on ubuntu 16.04, thanks for this great tutorials

[@hainguyen-it8598]

Tks you, after I bought your course on udemy (python for networking), I combined automation skill with 5 years of network exp, then nearly x2 my income with new position of network admin for a securities company. Really helpful

[@kritikapathak2728]

Hello Mr. David, thank you so much for this tutorial! And the Amazing part of all your videos are that on every step, you always motivates the learner. Thanks again!

[@nadirslh60]

Outstanding training methods David , it does not get any easier and any better than this. Gratitude Sir !

[@davidbombal]

Thanks for the comment!

[@FaeizMohammed]

Thank you so much sir, the mistake I made was using Eve-ng community edition. Switched back to GNS3 and I am using your videos. Now I have a lot of catching up too do. I really appreciate your efforts. A big thank you

[@abdimohamed1554]

Faeiz Mohammed I am curios. What was the issue with Eve-Ng community version?

[@FaeizMohammed]

Abdi Mohamed EvE Ng community has limitations unlike GNS3, also I switched to Ubuntu Linux to run GNS3 and I don’t run it on windows

[@Danth01gt]

This is awesome!!! I managed to create my first ever script (I have zero programming experience). Had a few hiccups with getting it to work with windows and understanding the logic but once I got it working I was able to perform a test script to log into a device at work and do a show command then exit. Thank you so much for the awesome tutorial!

[@davidbombal]

Congratulations! Thank you for watching.

[@bensake7921]

This was fantastic. I've been trying to pickup programming for a while (as a network engineer), but just couldn't see "WHY" I should be doing it. After seeing this, seeing the "why", it's now motivating to learn Python, and furthermore know where to start! Thanks for the great vid.

[@davidbombal]

Thanks Ben! All the best with your network automation journey.

[@abhishekshah11]

This is so beautiful. Thanks David!

[@NewtonMbazima]

Hi David, Thank you very much for all your hard work and this valuable set of learning material. i am enjoying the course on GNS3

[@davidbombal]

You're very welcome, thanks for the feedback Newton!

[@kenmurphy4259]

Ok, I'm hooked now! Thanks David, great tutorials. I want to start using python!

[@davidbombal]

That's great news Ken! Lots more programming coming in the next few days :)

[@xtensionxward3659]

i got recently CCNA certified and this is the first time i see programming and networking work together , this is so freakin magical ! i can only imagine the fun and euphoria i will feel having my router on GNS3 configured with loopback using a simple python script :D thanks for the motivation to move forward in network automation however i would love to see things that python can do that are not similar to just telneting and directly configuring the routers

[@davidbombal]

Really happy to hear that the video inspired you!

[@jeffsicuranza1168]

I went through the video, excellent introduction as well as re-enforcing the just do it approach. As many of us experienced network engineers recall this particular example is similar to using inspect or a ZOC like terminal emulator with a macro recorder that utilizes a script language. In ZOC for example you record your steps first on the device, then you just edit the macro recording for changes/variables(username, interface numbers, IP addresses etc.), resulting in REXX macro that I just run from ZOC to the router or switch. Very easy and powerful and I had to do this to deploy QoS commands to over 10,000 ports on a global network 6 years ago. The Python approach is especially flexible when you leverage the python interpreter on the actual network device’s OS. Since most network OS will be Linux based in one form or another will mostly likely now have a python 2.x or 3.x interpreter built in, just as Davide showed on the UBUNTU container. So, for some of the more OS specific commands you can just add something to the effect of “import cisco” and use the same concepts David outlined but on the device directly with script objects such as cisco.cli('show hostname') or cisco.cli("config t") or cisco.cli("interface vlan2") for example. You can save and run the script directly on the Cisco device for operators to run to make changes locally(a menu too), or run it from other network devices or centrally as David showed. I did this on a Nexus NXOS on 7k and 5k a few years back. Other venders will have their libraries as David mentioned that can be imported and run on the device directly or you access them remotely. Very powerful indeed. Great video and I look forward to the others. I always learn something from David.

[@davidbombal]

Great comments Jeff! Thank you for the input :)

[@carlosmunozii9318]

Excellent video! You just earned a new subscriber, cheers!

[@dattarayahonrao6928]

The best video tutorial for network engineer to start learning python.

[@davidbombal]

Thank you. I appreciate it!

[@danielshin3559]

here agreed Absolutely!

[@ipserv9539]

I really liked the way you are explaining things for the people who don't have any coding experience. Thanks for sharing videos about python.

[@davidbombal]

Glad it was helpful!

[@spidygamingb9120]

""the best way to do it ....is to do it""....excellent encouragement..

[@dattarayahonrao6928]

Thanks a lot!!! These is like teaching a Network Engineer how take baby steps towards python. Best help one can use to get started.

[@davidbombal]

Thank you! Each journey starts with one step :)

[@cil3150]

amazing David! straight forward!

[@abdulravoofka363]

Simply great video..Many thanks David. Loved it...looking forward for more network programmability using python scripts

[@davidbombal]

Thank you! Lots of Python and network programmability videos in the queue :)

[@abdulravoofka363]

Many thanks...Looking forward on this. And trying to best to follow with you...

[@jonathandominguezrebollo6564]

Great Content David... Congrats

[@g-man21]

You should have been in the Queen's Birthday honours list. David Bombal MBE ;). Thanks for the superb videos you put out on various Network tech, but this has taken me to the next stage and opens the door to so much more.

[@ujjalsamanta5841]

now I am very interest to learn python after see your lecture. ..thank you. .

[@zosmanovic9763]

I think you will change my life...as a netops guy this is Gold

[@gabimassi8265]

great, everything works fine so far... thank you so much... salute from Zurich

[@davidbombal]

You're welcome Gabi!

[@RishiKumar-uo9fp]

awesome stuff to learn David.....thanks a ton for this....

[@RezwanRahman]

your all video is very very very help full ..thanks a Ton "David Bombal"

[@davidbombal]

Thank you for watching Rezwan!

[@rajivnarayan5214]

Extremely useful introduction, that you very much.

[@HugoArmando35]

Wow beautiful! I had not seen this video!!!!

[@PROUDVETERAN1]

I'm a voice engineer always looking for better ways of doing what I do for many years. It's was inevitable that I needed to learn a new skill set. I was specifically looking for content your are providing. Thank You!!

[@davidbombal]

Thank you for watching Joon!

[@MatheusHenrique-jz1dc]

Excellent David thank you!!

[@bikramjeetsandhu2382]

Thanks David - You are awesome 👏🏻

[@anthonysbarat]

Wow, really cool! Thank you for sharing this knowledge!

[@davidbombal]

Thanks Anthony, I'm glad that helped.

[@PrabhatKumar-pc4ec]

Thanks David ...:) i was searching for this kind of tutorial....

[@davidbombal]

Thank you Prabhat! Glad to hear the tutorial was helpful :)

[@cresrey5961]

Damn! David why you are so great! Your a rockstar!

[@karubees]

Great video brother David!

[@davidbombal]

Thank you!

[@ER_aka_RAM]

Cheers for the attention to detail 🍻

[@CarlosLopez-vx5wb]

Great video David and thanks for share your acknowledge!

[@davidbombal]

Thank you for watching Carlos!

[@Mohammad_1234uk]

Thank you so much David

[@alinmuntean2916]

LOVE IT!!

[@muhammadusmanali9779]

Sir, Your Videos are very good that motivate me to learn the python. Because I am Network Administrator and I love to learn the New Technologies specially Cisco, Linux, GNS3, Python. Keep motivate us. Thanks

[@davidbombal]

Thank you! I am glad you are enjoying my videos Muhammad!

[@victormelothemaster]

you will need to learn Cisco, Linux ,Gns3 and Python to have a better idea of what David is doing because he is using all those tools and command here! Go easy on yourself and try to learn one by one

[@dhilipkumar2567]

Good explanation David😊 Thanks much!

[@davidbombal]

Thank you!

[@antikoerper256]

10:44 - very neat, thanks for this tutorial

[@haxid.]

Thanks you a lot!! im a really beegginer to code. your video really empower me to do more !!

[@davidbombal]

Thanks Christian, I'm glad that helped.

[@ngstylenew-grow9779]

Great video David!

[@davidbombal]

Thank you for watching :)

[@jasonme3557]

Very nice. TY David.

[@davidbombal]

Thank you Jason

[@user-xb4xr5dd1w]

Mr.Bombal biggest thanks (sorry for my bad english), good words about just do it... wery good practical learning...

[@davidbombal]

Thank you! You English is great... no need to apologise :)

[@ErnieJunValledorbunny]

Very detailed explanation.

[@joseluisquintero4076]

Excelente! Gracias por el contenido. Saludos desde Venezuela

[@davidbombal]

De nada Jose! Enjoy the videos :)

[@datsun7777]

Great video. Thanks David.

[@davidbombal]

Thanks. Stay tuned.

[@MuhammadKhan-yl7mt]

Very nicely walked through, thanks.

[@davidbombal]

Thank you

[@juanlyon3368]

David Bombal!!! a big thank you

[@davidbombal]

Thanks, Juan!

[@leonidas300755]

Beatifull! Thank you!

[@SaveraVikasBarjo]

great intro of python for Network folks. Thanks David :) most of the #PythonForNetworkEngineers video are just the python videos. but this really helped me to understand the basic application of python in networks devices.

[@davidbombal]

Thank you! I'm glad you are enjoying the videos :)

[@moussainfotech8683]

Thanks a lot for this cours is very important content

[@synthc1786]

thank so much Mr David!

[@gladegel123]

I like the way you are teaching for network engineer who are Python beginners.

[@davidbombal]

Glad to hear that and thank you :)

[@user-ck4ix6re2v]

That's incredible. Thank you

[@davidbombal]

Thanks for the comment, you're welcome!

[@voipgenius5765]

i love the way you teach us .... great

[@davidbombal]

Thank you. I appreciate it!

[@renaneler]

Thanks, great tutorials!

[@davidbombal]

Thank you for watching!

[@maboxdiamond3812]

Thank you David

[@Notoraj]

Thank you for your those inspiring words

[@davidbombal]

You're welcome! Much appreciated :)

[@Danth01gt]

Good stuff!!! This could have been a great thing to use to make QoS changes to 260ish routers I had to do a while back.

[@davidbombal]

Thank you for watching. Network automation can really save time :)

[@ldbisono]

Thanks very much David for sharing your knowledge! from RD

[@davidbombal]

Thank you Luis!

[@manojkbn]

Excellent !!!

[@kevindoom]

you are the best!!!

[@beatzbyDAVE]

I can only thank you. thank you, sir

[@davidbombal]

You're very welcome :)

[@ronniewatson322]

Wow that was cool!

[@davidbombal]

Glad you enjoyed the video Ronnie!

[@farajibader1913]

You are the best .. Very simple explination to a hard subject .. Can yiu please recommand books that are related to this ?

[@refaiabdeen5943]

Cheers Mate !!

[@abdullahabdi9093]

Just amazing

[@123456789lkjkm]

Thanks David, that is great videos.

[@davidbombal]

Thanks :)

[@123456789lkjkm]

Dear David, What's " if password: " mean?

[@klittlet005]

Thank you! I have GNS3 running on Ubuntu. If my thinking is correct, I should be able to run the python scripts without adding a Linux box into the GNS3 environment. Years ago I have used bash scripting to send IP, username, password and commands using Expect . And often gathering the show output for analysis. I'll look for your training material after I finish my intro python class.

[@newphone3594]

Amazing tutorial. Thank you. I have a question how does Python really help speed up configuration? I think putting everything in a notepad and copying is much faster. Please prove me wrong if I am.

[@evletovnerslephomaniac]

I don't use Docker on my Ubuntu host mashine, so I got an error in Python 2.7.13, which is default at this moment: Traceback (most recent call last): File "./python.py", line 11, in tn = telnetlib.Telnet(HOST) Any thoughts?

[@samama4u]

Hi, Thank you dear for you great work.

[@davidbombal]

You're welcome Abdul. Thanks for the feedback!

[@quality89]

your very good, thanks

[@AnonymousC]

YOU ARE THE MAN DAVID

[@davidbombal]

Thanks!

[@AnonymousC]

Honestly i am still a beginner ( in python , makes me struggle in some parts ) , but this course made me transition into someone else with practical skills , Sir if you ever release a new cisco + python programmability course ( Paid or free ) , immediately i will be the first customer to sign in ..looking forward to it Regards

[@davidbombal]

I am working on a course. Thank you for the feedback :)

[@Prashanthkadem]

TQ man!!! informative.

[@davidbombal]

Thank you!

[@chikkivenu6632]

Hi david, I found the issue of edit config not working on host machine of windows 7. However i did work around for the same by editing /etc/network/interfaces file in ubunto. nano /etc/network/interfaces and saving the file and rebooting it. However i do have a question for you. I don't understand from where is it getting ip from? who is DHCP provider? I do not have any network in my home network with that IP Subnet. Thank you Chikkis

[@rchapoteau]

I'm looking at this and I can't see how to make the ubuntu guest work if there is a proxy involved. Are there directions involved on that somewhere?

[@bigzy7]

Hi I'm a newbie, I would like to know if we could initially setup a router or switch with a python script that would include all configurations including interface IP addresses as well as telnet and ssh passwords/usernames etc..

[@swapnilchavan5708]

Hello David, Thanks for the course. it is very helpful for the network engineer who are python beginners. could you pls suggest from where I should get Switch IOS for GNS 3, Ubuntu container. Thanks, Swapnil

[@nehasharma-1909]

Sir, Can we write a script which takes ping rtt value & wait for 2*rtt time and again ping?

[@tega2rule]

thank you David

[@davidbombal]

My pleasure!

[@subhashdabhade3960]

Hi David, Its nice video series. Thanks shring such a fantastic video. Moreover i have query, Whicgh version of GNS3 required for python?

[@EvandroMeneguella]

Hi, I cannot install paramiko or netmiko due to business restrictions. Is there an alternative to connect using SSH to network devices?

[@jorgegill1225]

It'd be cool if you had explained your GNS3 configuration

[@mahedihasanshaon1657]

wowwwooww that's awesome

[@ductrannhu1960]

thank you for the video :D

[@davidbombal]

You're welcome!

[@manuelvillapudua460]

if you are trying to do this lab, it looks like there is a timeout when accessing the telnet library. would anyone know of another telnet repository one can reference to continue on with this lab?