MUST READ: SR(x)6 – Snake Oil Or Salvation?

I wanted to write a “SRv6 makes no little sense” blog post for a long while, but there were always more relevant topics to focus on. Fortunately I won’t have to write it anytime soon; Ethan Banks did a fantastic job with SR(x)6 - Snake Oil Or Salvation?. Make sure you read it before attending the next “SRx6 will save the world” vendor presentation.

Worth Reading: How CEOs think

Robert Graham wrote a great article explaining why CEOs don’t care much about cybersecurity or any other non-core infrastructure (including networking, unless you happen to be working for a service provider). It’s a must-read if you want to understand the **** you have to deal with in enterprise environments.

OMG, Not Again: New Mobile Internet Protocol Vulnerabilities

Every now and then a security researcher “discovers” a tunneling protocol designed to be used over a protected transport core and “declares it vulnerable” assuming the attacker can connect to that transport network… even though the protocol was purposefully designed that way, and everyone with a bit of clue knew the whole story years ago (and/or it’s even documented in the RFC).

It was MPLS decades ago, then VXLAN a few years ago, and now someone “found” a “high-impact vulnerability” in GPRS Tunnel Protocol. Recommended countermeasures: whitelist-based IP filtering. Yeah, it’s amazing what a wonderful new tool they found.

Unfortunately (for the rest of us), common sense never generated headlines on Hacker News (or anywhere else).

Worth Reading: entr: Rerun Your Build when Files Change

Julia Evans recently described another awesome Linux tool: entr allows you to run a bash command every time a watched file changes (and it works on Linux and OSX).

I wish I found it years ago…

Worth Reading: Written communication is remote work super power

Snir David wrote a great article explaining why you should focus on documenting stuff you do instead of solving other people’s challenges (or putting out fires) on Slack/Zoom/whatever. Enjoy ;)

Worth Reading: Working with TC on Linux systems

Here’s one of the weirdest ideas I’ve found recently: patch together two dangling ends of virtual Ethernet cables with PBR.

To be fair, Jon Langemak used that example to demonstrate how powerful tc could be. It’s always fun to see a totally-unexpected aspect of Linux networking… even though it looks like the creators of those tools believed in Perl mentality of creating a gazillion variants of line noise to get the job done.

Worth Reading: Lies, Damned Lies, and Keynotes

Got sick and tired of conference keynotes? You might love the Lies, Damned Lies, and Keynotes rant by Corey Quinn. Here are just two snippets:

They’re selling a fantasy, and you’ve been buying it all along.

We’re lying to ourselves. But it feels better than the unvarnished truth.

Enjoy!

Summer Break 2020

Almost 30 webinars, an online course, and over 140 blog posts later it’s time for another summer break.

While we’ll do our best to reply to support and sales requests (it might take us a bit longer than usual), don’t expect anything deeply technical for the new two months… but of course you can still watch over 280 hours of existing content, listen to over 100 podcast episodes, or read over 3500 blog posts.

We’ll be back with tons of new content in early September.

In the meantime, automate everything, get away from work, turn off the Internet, and enjoy a few days in your favorite spot with your loved ones!

BGP Navel Gazing on Software Gone Wild

This podcast introduction was written by Nick Buraglio, the host of today’s podcast.

As we all know, BGP runs the networked world. It is a protocol that has existed and operated in the vast expanse of the internet in one form or another since early 1990s, and despite the fact that it has been extended, enhanced, twisted, and warped into performing a myriad of tasks that one would never have imagined in the silver era of internetworking, it has remained largely unchanged in its operational core.

The world as we know it would never exist without BGP, and because of the fact that it is such a widely deployed protocol with such a solid track record of “just working”, the transition to a better security model surrounding it has been extraordinarily slow to modernize.

Adapting Network Design to Support Automation

This blog post was initially sent to the subscribers of my SDN and Network Automation mailing list. Subscribe here.

Adam left a thoughtful comment addressing numerous interesting aspects of network design in the era of booming automation hype on my How Should Network Architects Deal with Network Automation blog post. He started with:

A question I keep tasking myself with addressing but never finding the best answer, is how appropriate is it to reform a network environment into a flattened design such as spine-and-leaf, if that reform is with the sole intent and purpose to enable automation?

A few basic facts first:

Security Aspects of Using Smart NICs

After I published the blog post describing how infrastructure cloud provides (example: AWS) might use smart Network Interface Cards (NICs) as the sweet spot to implement overlay virtual networking, my friend Christoph Jaggi sent me links to two interesting presentations:

• Can you still trust your network card
• The Jedi Packet Trick Takes over the Deathstar

Both presentations describe how you can take over a smart NIC with a properly crafted packet, and even bypass CPU on a firewall using smart NICs.

Worth Reading: Starting Your Network Automation Journey

Daniel Teycheney published an excellent blog post with numerous hints on starting your automation journey including:

• Which programming language should you start with?
• Python or Ansible?
• What about Terraform?
• What resources could you use?

Worth Reading: When Security Takes a Backseat to Productivity

Brian Krebs wrote an interesting analysis of CIA’s Wikileaks report. In a nutshell, they were a victim of “move fast to get the mission done” shadow IT.

It could have been worse. Someone with a credit card could have started deploying stuff in AWS ;))

Not that anyone would learn anything from the PR nightmare that followed.

Internet Behind Iron Curtain

A while ago Russ White invited me to be a guest on his fantastic History of Networking podcast, and we spent almost an hour talking about networking in 1980s and 1990s in what some people love to call “behind iron curtain” (we also fixed that misconception).

Bridging Loops in Disaster Recovery Designs

One of the readers commenting the ideas in my Disaster Recovery and Failure Domains blog post effectively said “In an active/passive DR scenario, having L3 DCI separation doesn’t protect you from STP loop/flood in your active DC, so why do you care?”

He’s absolutely right - if you have a cold disaster recovery site, it doesn’t matter if it’s bombarded by a gazillion flooded packets per second… but how often do you have a cold recovery site?

Worth Reading: Lessons Learned from 20 Years of Hype Cycles

Michael Mullany analyzed 20 years of Gartner hype cycles and got some (expected but still interesting) conclusions including:

• Nobody noticed major technologies even when they were becoming mainstream
• Lots of technologies just die, others make progress when nobody is looking
• We might get the idea right and fail badly at implementation
• It takes a lot longer to solve some problems than anyone expected

Enjoy the reading, and keep these lessons in mind the next time you’ll be sitting in a software-defined, intent-based or machine-learning $vendor presentation.

EVPN: The Great Unifying Theory of VPN Control Planes?

I claimed that “EVPN is the control plane for layer-2 and layer-3 VPNs” in the Using VXLAN and EVPN to Build Active-Active Data Centers interview a long long while ago and got this response from one of the readers:

To me, that doesn’t compute. For layer-3 VPNs I couldn’t care less about EVPN, they have their own control planes.

Apart from EVPN, there’s a single standardized scalable control plane for layer-3 VPNs: BGP VPNv4 address family using MPLS labels. Maybe EVPN could be a better solution (opinions differ, see EVPN Technical Deep Dive webinar for more details).

Network Reliability Engineering Should Be More than Software or Automation

This blog post was initially sent to the subscribers of my SDN and Network Automation mailing list. Subscribe here.

In late 2018 Juniper started aggressively promoting Network Reliability Engineering - the networking variant of concepts of software-driven operations derived from GIFEE SRE concept (because it must make perfect sense to mimic whatever Google is doing, right?).

There’s nothing wrong with promoting network automation, or infrastructure-as-code concepts, and Matt Oswalt and his team did an awesome job with NRE Labs (huge “Thank you!” to whoever is financing them), but is that really all NRE should be?

SuzieQ with Dinesh Dutt and Justin Pietsch on Software Gone Wild

In early May 2020 I wrote a blog post introducing SuzieQ, a network observability platform Dinesh Dutt worked on for the last few years. If that blog post made you look for more details, you might like the Episode 111 of Software Gone Wild in which we went deeper and covered these topics:

• How does SuzieQ collect data
• What data is it collecting from network devices
• What can you do with that data
• How can you customize and extend SuzieQ

Example: Fully-Automated AWS Network Infrastructure Deployment

Regular readers of my blog probably remember the detailed explanations Erik Auerswald creates while solving hands-on exercises from our Networking in Public Cloud Deployments online course (previous ones: create a virtual network, deploy a web server).

This time he documented the process he went through to develop a Terraform configuration file that deploys full-blown AWS networking infrastructure (VPC, subnets, Internet gateway, route tables, security groups) and multiple servers include an SSH bastion host. You’ll also see what he found out when he used Elastic Network Interfaces (spoiler: routing on multi-interface hosts is tough).