AX.25 over D-Star

Setting up AX.25 over 1200bps was easy enough. For 9600 I got kernel panics on the raspberry pi, so I wrote my own AX.25 stack.

But I also want to try to run AX.25 over D-Star. Why? Because then I can use radios not capable of 9600 AX.25, and because it’s fun.

It seems that radios (at least the two I’ve been working with) expose the D-Star data channel as a byte stream coming over a serial connection. Unlike working with a TNC you don’t have to talk KISS to turn the byte stream into packets, and vice versa.

IC9700 setup

The first hurdle to overcome, because we want to send binary data, is to escape the XON/XOFF flow control characters that the IC9700 mandates. Otherwise we won’t be able to send 0x13 or 0x11. Other bytes seem to go through just fine.

So I wrote a wrapper for that, taking /dev/ttyUSB1 on one side, and turning it into (e.g.) /dev/pts/20 for use with kissattach.

$ ./dsax /dev/ttyUSB1
/dev/pts/20

$ kissattach /dev/pts/20 radio
$ kissattach -p radio -c 2     # See below

Set Menu>Set>DV/DD Set>DV Data TX to Auto, for “automatic PTT”. As Continue reading

How to Pass CCNP ENARSI – Exam Review

AWS Ride Along Blog & YouTube Series

So as many of you know, I decided in 2021 that in my “spare time” I was going to start learning more about AWS. Well that didn’t go so well… lol… so I decided to give myself a “goal” and... Read More ›

The post AWS Ride Along Blog & YouTube Series appeared first on Networking with FISH.

The 7 Requirements of Highly Effective Load Balancers 

As Stephen R. Covey stated in his popular book, The 7 Habits of Highly Effective People, “True effectiveness requires balance.” VMware agrees. And when it comes to accelerating modern application delivery, true application effectiveness requires a modern load balancer. So, with a respectful nod to Stephen R. Covey, here are the seven requirements of highly effective load balancers.  

1. Be proactive with self-service. Move away from “create a ticket and wait” developer experiences to self-service, role-based access control for owners to provision, troubleshoot, and monitor their own apps.
2. Begin with the end in mind with on-demand autoscaling. Automation drives great user experiences. Plan for peak usage times without causing overprovisioning and idle capacity.
3. Put things first with a 100 percent software solution. The need to support on-premises data center and multi-cloud deployments means that enterprises need to choose applications that work consistently across different environments with a single point of orchestration.
4. Think win-win with real-time insights and visibility into application traffic. A modern load balancer should collect real-time application telemetry and provide insights into each transaction and end-user patterns.
5. Seek first to understand, then to be understood with security insights. App vulnerabilities stem from incorrect access control policies Continue reading

Real-time telemetry from a 5 stage Clos fabric

docker run --rm -it --privileged --network host --pid="host" \
  -v /var/run/docker.sock:/var/run/docker.sock -v /run/netns:/run/netns \
  -v ~/clab:/home/clab -w /home/clab \
  ghcr.io/srl-labs/clab bash

curl -O https://raw.githubusercontent.com/sflow-rt/containerlab/master/clos5.yml

containerlab deploy -t clos5.yml

Note: The 3 stage Clos topology, clos3.yml, described in the previous article is also available.

What is CCNP ENARSI

How to Make the Most of Kubernetes Environment Variables

In traditional systems, environment variables play an important role, but not always a crucial one. Some applications make more use of environment variables than others. Some prefer configuration files over environment variables. However, when it comes to Kubernetes, environment variables are more important than you might think. It’s partially due to the way containers work in general and partially due to the specifics of Kubernetes. In this post, you’ll learn all about environment variables in Kubernetes. Traditionally, environment variables are dynamic key-value variables that are accessible to any process running on the system. The Basics Let’s start with the basics. What are environment variables and why do they exist? Traditionally, environment variables are dynamic key-value variables that are accessible to any process running on the system. The operating system itself will set many environment variables that help running processes understand the specifics of the system. Thanks to this, software developers can include logic in their software that makes the programs adjustable to a specific operating system. Environment variables also hold a lot of important information about the user, things like username, preferred language, user home directory path and many other useful bits of information. User-Defined Environment Variables Dawid Ziolkowski Dawid Continue reading

Five ways to get started with network automation

As many of you know, Red Hat Ansible Automation Platform is a highly flexible IT automation platform that can automate your Linux and Windows instances, your VMware private cloud, your AWS, Azure or Google public cloud, and even your security infrastructure.  Today I want to write about one of my favorite use-cases; using Ansible Automation Platform for network automation. It provides easy, highly customizable automation for your routers and switches so you can automate them just like any other IT infrastructure.

However, even though network automation has become increasingly popular, most organizations are still managing their network infrastructure manually by a CLI or GUI. Why is this? This manual CLI work often means that network engineers are reactive and constantly drowning with break-fix network issues because of manual mis-configurations, or the inability to implement change quickly and efficiently.

Because network engineers are so busy firefighting in their day job, they don’t have time to look at a new activity like automating, even though automation will save them time and money in the long run. I fundamentally believe that network automation is not an all or nothing situation.  You need to adopt network automation in small increments so you Continue reading

The Post-Quantum State: a taxonomy of challenges

At Cloudflare, we help to build a better Internet. In the face of quantum computers and their threat to cryptography, we want to provide protections for this future challenge. The only way that we can change the future is by analyzing and perusing the past. Only in the present, with the past in mind and the future in sight, can we categorize and unfold events. Predicting, understanding and anticipating quantum computers (with the opportunities and challenges they bring) is a daunting task. We can, though, create a taxonomy of these challenges, so the future can be better unrolled.

This is the first blog post in a post-quantum series, where we talk about our past, present and future “adventures in the Post-Quantum land”. We have written about previous post-quantum efforts at Cloudflare, but we think that here first we need to understand and categorize the problem by looking at what we have done and what lies ahead. So, welcome to our adventures!

A taxonomy of the challenges ahead that quantum computers and their threat to cryptography bring (for more information about it, read our other blog posts) could be a good way to approach this problem. This taxonomy should Continue reading

The quantum solace and spectre

Not only is the universe stranger than we think, but it is stranger than we can think of
— Werner Heisenberg

Even for a physicist as renowned as Heisenberg, the universe was strange. And it was strange because several phenomena could only be explained through the lens of quantum mechanics. This field changed the way we understood the world, challenged our imagination, and, since the Fifth Solvay Conference in 1927, has been integrated into every explanation of the physical world (it is, to this day, our best description of the inner workings of nature). Quantum mechanics created a rift: every physical phenomena (even the most micro and macro ones) stopped being explained only by classical physics and started to be explained by quantum mechanics. There is another world in which quantum mechanics has not yet created this rift: the realm of computers (note, though, that manufacturers have been affected by quantum effects for a long time). That is about to change.

In the 80s, several physicists (including, for example, Richard Feynman and Yuri Manin) asked themselves these questions: are there computers that can, with high accuracy and in a reasonable amount of time, simulate physics? And, specifically, can they Continue reading

Top 7 next-generation firewall vendors

With more employees accessing network resources remotely, the increase in companies deploying hybrid cloud architectures, and the overall escalation of security threats, firewall technology is critical to the integrity, security and the very lifeblood of any enterprise.  Traditional firewalls are security devices which inspect traffic at the point of network ingress/egress, as well as provide Virtual Private Network (VPN) and encryption capabilities. Firewalls watch traffic by state, port and protocol, and control the flow of the traffic passing through. In a traditional firewall, advanced security features are typically provided by external appliances and services that live outside the firewall platform.To read this article in full, please click here

Feedback: DMVPN Webinars

Some webinars on ipSpace.net are ancient (= more than a decade old). I’m refreshing some of them (the overhaul of Introduction to Virtualized Networking was completed earlier this month); others will stay as they are because the technology hasn’t changed in a long while, and it’s always nice to hear someone still finds them useful. This is a recent feedback I got on the DMVPN webinars:

As with any other webinar I have viewed on ipspace.net, this one provides the background as to why you may or may not want to do certain things and what impact that may have (positive or negative) on your network. Then it digs into the how of actually doing something. Brilliant content as always.

IPSpace.net is my go-to for deep dives on existing and emerging technologies in the networking industry. No unnecessary preamble. Gets straight to the point of why you are looking at a specific technology and explains the what and the why before getting into the how.

Feedback: DMVPN Webinars

Some webinars on ipSpace.net are ancient (= more than a decade old). I’m refreshing some of them (the overhaul of Introduction to Virtualized Networking was completed earlier this month); others will stay as they are because the technology hasn’t changed in a long while, and it’s always nice to hear someone still finds them useful. This is a recent feedback I got on the DMVPN webinars:

As with any other webinar I have viewed on ipspace.net, this one provides the background as to why you may or may not want to do certain things and what impact that may have (positive or negative) on your network. Then it digs into the how of actually doing something. Brilliant content as always.

IPSpace.net is my go-to for deep dives on existing and emerging technologies in the networking industry. No unnecessary preamble. Gets straight to the point of why you are looking at a specific technology and explains the what and the why before getting into the how.

Data Center Network Automation has a Data Problem

Localisation isn’t translation

If you only have your app in English then you’ll still be understood[1] by the new market whose official language isn’t English.

If you show farenheit (a word I can’t even spell), then 96% of the world cannot understand your app. At all.

For most of the west I would argue that translation doesn’t even matter at all, but you cannot have your app start your weeks on Sunday, you cannot show fahrenheit, or feet, or furlongs, or cubits or whatever US-only units exist. And you cannot use MM/DD/YY.

NONE of these things are tied to language. Most users of English don’t want any of this US-only failure to communicate.

[1] While most of the world doesn’t speak English fluently, they may know words. And they can look up words. You cannot “look up” understanding fahrenheit or US-only date formats.

Go programs are not portable

A while ago I was asked why I wrote Sim in C++ instead of Go. I stumbled upon my answer again and realized it could be a blog post.

So here’s what I wrote then. I think I stand by it still, and I don’t think the situation has improved.

Why not write portable system tools in Go

My previous experience with “low level” things in Go (being very careful about which syscalls are used, and in which order) has had some frustrations in Go. Especially with portability. E.g. different definitions of syscall.Select between BSDs and Linux, making me have to use reflection at some points. (e.g. see this Go bug.

And to work around those things Go unfortunately uses the antipattern of (essentially) #ifdef __OpenBSD__, which we’ve known for decades is vastly inferior to checking for specific capabilities.

To me the Go proverb “Syscall must always be guarded with build tags” essentially means “Go is not an option for any program that needs to be portable and may at some point in the future require the syscalls package”. And since this tool is meant to be portable, and calls what would be syscall.Setresuid, Continue reading

Events. My experience from taking part in NANOG #84 Hackathon

Hello my friend,

collaboration, team work, team spirit… These and other similar words we are using quite often to show the importance of working together to achieve something big. Especially, if you have very limited time. This is a good description of the hackathon – the team effort to achieve something big (i.e., MVP of working product) in a short term (i.e., in 24 hours). Let’s see what’s that all about.

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No part of this blogpost could be reproduced, stored in a 

retrieval system, or transmitted in any form or by any 

means, electronic, mechanical or photocopying, recording, 

or otherwise, for commercial purposes without the 

prior permission of the author.

What Was the Hackathon?

There are many hackathons worldwide. The trend we observe now is that many technical events have hackathon as a warm-up event or a part of the main program. In this case, the event was NANOG 84, which is one of the biggest gatherings for all Service Providers, Telco equipment vendors, and system integrators in North America. It is a massive opportunity to learn some interesting things from some leading companies, like their experience and lessons learned Continue reading

charmed-kubernetes-on-bare-metals

https://github.com/kashif-nawaz/charmed-kubernetes-on-bare-metals

Marvell’s Building Blocks For Carrier Edge, 5G Networking

This article was originally posted on the Packet Pushers Ignition site on December 17, 2020. 5G and edge computing are mainstays of almost every tech company’s growth strategy, but their combined potential for market disruption is acute among network equipment vendors, carriers, and related component suppliers. Both trends have been brewing for years, but have […]

The post Marvell’s Building Blocks For Carrier Edge, 5G Networking appeared first on Packet Pushers.

Interop IP infusion and MikroTik: part 2 – VPLS

VPLS is a pretty common technology in ISPs to either sell layer 2 services or backhaul traffic to a centralized aggregation point to conserve IPv4 space; check out more on that here.

How can I take advantage of segment routing but still deliver the same services? We already looked at how to setup the label switched paths utilizing IP Infusion as a segment routing mapping server in this interop post. Now let’s see how we can deliver a VPLS service over this with mikrotik as a provider edge router.

Delivering a service with a L2VPN

After setting up the IGP and label distribution between the PEs we will start building the L2VPN.

Why a BGP signaled VPLS session instead of LDP signaled VPLS?

In the segment-routing domain there is no LDP running. However, some vendors support static pseudowires or other methods to bring up a targeted LDP session for VPLS. I did some basic testing here couldn’t easily identify the right combination of knobs to make this work. Don’t worry; I’ll come back to it.

BGP signaled VPLS is a standards based technology that both vendors support.

First thing we need to do after having loopback reachability is to build Continue reading