Nokia (Alcatel-Lucent). Configuring Packet (IP) Filters

June 24, 2015

Packet filters (or in Cisco terminology Access Control Lists, aka ACL) are one of the most used tools in a network engineer’s tool set. Blocking telnet/ssh access, restricting specific traffic flows, implementing policy-based routing or NATing - all of these tasks use IP filter’s capabilities.

In this example I’ll show you how to configure a basic SSH-blocking IP filter on a Nokia (Alcatel-Lucent) SROS running TiMOS-B-12.0.R8.

Roman Dodin

Eagerness to learn & passion to share

Netdevops @ Nuage Networks

Russia

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Creating a Bootstrap based front-end for your simple REST service

Jul 7, 2019

Not a single day goes by without me regretting I haven’t mastered any front-end technology like React/Angular or the likes. Why would a network engineer want to step into the game that seems orthogonal to its main area of expertise, one might ask?

Truth be told, I wasn’t born with an urge to learn anything that has javascript under the hood, but over the years, working within the network/backend silos, I realized, that being able to create a simple front-end service is a jewel that fits every crown, no matter what title you wear.

This tutorial is based on the task real task of building up a web interface (pycatjify.netdevops.me) for the pycatjify REST API service deployed as a serverless function. The end result is a simple, completely free and reusable Bootstrap based front-end boilerplate which can be used as a foundation for a similar task.

Creating Google Cloud Platform Function with Python and Serverless

Jun 6, 2019

serveless Two years ago I shared my experience on building the AWS Lambda function for a python project of my own. And a few days ago I stumbled upon a nice opensource CLI tool that I immediately wanted to transform in a web service.

Naturally, a simple, single-purpose tool is a perfect candidate for function-as-a-service (FaaS), and since I had past experience with AWS Lambda, this time I decided to meet its Google’s sibling - Google Cloud Function.

In this post we’ll discover how to take a python package with 3rd party dependencies, make a GCP Function from it and deploy it without a single click in the UI - all without leaving the IDE.

[Project’s source code]

How to download an M3U/M3U8 playlist (stream) without a special software

Jun 6, 2019

I love the tech conferences that share the recordings of the sessions without hiding behind the registration or a pay wall. Luckily the trend to share the knowledge with a community openly is growing, yet you still can find a nice talk hidden behind the above mentioned walls.

Sometimes an easy registration is all it takes, but then, how do you watch it offline? For example, I do love to catch up with with the recent trends and experiences while being on a plane, meaning that I just cant afford to be hooked up to the Internet.

If a talk is published on the YouTube, you are good to go and download it with any web service that pops up in the google search by the term “Youtube download”. But what do we do when the video is hosted somewhere in the CDN and is served as a dynamic playlist of *.ts files?

Here I share with you an easy way to download the videos from an m3u/m3u8 playlist.

Saturating the network with FTP

Nov 11, 2018

While working on the Ipanema Wan Opt VNF integration with Nuage Networks I stumbled upon an interesting case which required to max out the network with FTP traffic. The tricky point there was to create the FTP connection which won’t be limited by the disk IO performance. Especially, considering that the disks were kind of slow in the setup I had.

It turns out, you can use the in-memory devices in the FTP communication path /dev/zero -> /dev/null, ruling out the slowliness that could have been added by the disks. Lets figure out how to do that!

Prepping up for and passing the Certified Openstack Administrator Exam

Nov 11, 2018

Shortly after I passed AWS CSA exam I went on a hunt for the next certification to claim. Decided to tackle the Openstack COA certification first saving the Docker/Kubernetes certification for a later occasion.

There is a common joke floating around: “Oh, is Openstack still a thing?” - yes, its pretty much still a thing, especially in the Telecom area where VMs are the only viable option for the most of the cases (think VNFs).
Openstack also powers our teams public SDN lab - NuageX - that allows to provision a fully functional Nuage environment in a matter of minutes. So I wanted to get a better operational knowledge of Openstack to be able to support and tune the platform if necessary.

Disclaimer: I took the recently updated COA exam which is based on the Openstack Pike release, although I did not face any Pike-specific questions during the exam. This does not mean that the exam content will stay the same throughout the course evolution, so watch out for the updates.

Prepping up for and passing the AWS Certified Solution Architect - Associate

May 5, 2018

On May 11th I passed the AWS Certified Solution Architect Associate exam which was harder then I expected. In this memo I will outline how I prepared to this exam, what topics you better pay more attention to and some tips and hints I could give to anyone going for AWS CSA exam.

Disclaimer: I took the original AWS CSA exam, not the one that was launched in Feb 2018; this older version is only available to schedule till August 2018. After that date the newer version of this exam will be the only one available. Watch out, it has a new set of objectives.

Uploading multiple files to AWS S3 in parallel

Mar 3, 2018

Have you ever tried to upload thousands of small/medium files to the AWS S3? If you had, you might also noticed ridiculously slow upload speeds when the upload was triggered through the AWS Management Console. Recently I tried to upload 4k html files and was immediately discouraged by the progress reported by the AWS Console upload manager. It was something close to the 0.5% per 10s. Clearly, the choke point was the network (as usual, brothers!).

Comer here, Google, we need to find a better way to handle this kind of an upload.

How to add YAML highlight in Highlight.js?

Nov 11, 2017

SROS Rootifier or how to flatten 7750 SR config

Nov 11, 2017

Back in the days when I mostly did routing stuff I spent the whole day configuring SROS devices via SSH. And once in a while I saw that SSH session or its server part (or even underlying connection) glitched, resulting in a corrupted lines feeded to the device.

What was also quite common is to make a mistake (i.e. syntax one) in a single line and watch like the rest of config got applied to the wrong context.

These sad facts pushed me to create a rootifier CLI script, that was converting tree-like SROS config into flattented (aka rooted) fashion.

Now I decided to make a web service of that script, that is publicly available at https://rootifier.netdevops.me/

Flask application in a production-ready container

Nov 11, 2017

Flask documentation is very clear on where is the place for its built-in WSGI application server:

While lightweight and easy to use, Flask’s built-in server is not suitable for production as it doesn’t scale well and by default serves only one request at a time.

So how about I share with you a Dockerfile that will enable your Flask application to run properly and ready for production-like deployments? As a bonus, I will share my findings discovered along the way of building this container image.

nginx-uwsgi-flaks-alpine-docker