TL&DR: No.

Here’s another never-ending vi-versus-emacs-type discussion: merchant silicon like Broadcom Trident cannot forward small (64-byte) packets at line rate. Does that matter, or is it yet another stimulating academic talking point and/or red herring used by vendor marketing teams to justify their high prices?

Here’s what I wrote about that topic a few weeks ago:

In the previous blog post in this series, we figured out that you might not need link-layer addresses on point-to-point links. We also started exploring whether you need network-layer addresses on individual interfaces but didn’t get very far. We’ll fix that today and discover the secrets behind IP address-per-interface design.

In the early days of computer networking, there were three common addressing paradigms:

After I created the Segment Routing lab to test the relationship between Node Segment ID (SID) and MPLS labels, I was just a minor step away from testing BGP-free core with SR-MPLS.

I added two nodes to my lab setup, this time using IOSv as those nodes need nothing more than EBGP support (and IOSv is tiny compared to IOS XE on CSR):

Minh Ha left a lengthy comment to my There’s No Recipe for Success blog post, adding an interesting perspective of someone who had to work really hard to overcome coming from a third-world country.

Ivan, I happened to read “Deep Work: Rules for Focused Success in a Distracted World” recently so I can attest that it does provide some valuable advices on how to do things well. Some of the overarching themes are stay focused and cut off unnecessary noise/drain the shallow. The author also suggests removing your social media account if you can’t see how it add values to your work/business, as social media can create attention disorder, seen in many young kids these days.

Ethan Banks wrote the best one-line description of the crazy stuff we have to deal with in his When Stretching Layer Two, Separate Your Fate blog post:

No application should be tightly coupled to an IP address. This common issue should really be solved by application architects rebuilding the app properly instead of continuing like it’s 1999 while screaming YOLO.

Not that his (or my) take on indisputable facts would change anything… At least we can still enjoy a good rant ;)

If you ever get a feeling the grass is greener on the other (startup) side, read My Secret Startup Past by Amy Hoy, and if you think about starting your business, read all the other stuff she wrote. I wish I knew of her when I was starting ipSpace.net a decade ago.

A few weeks ago we covered transparent bridging fundamentals, now it’s time to recap IP routing fundamentals… and then we’ll be ready to compare the two.

I love hearing real-life “how did I start my automation journey” stories. Here’s what one of ipSpace.net subscribers sent me:

• Make peace with your network engineering soul and mind and open up to the possibility that the world has moved on to something else when it comes to consuming apps and software. Back in 2017, this was very hard on me :)

In the world of ubiquitous Ethernet and IP, it’s common to think that one needs addresses in packet headers in every layer of the protocol stack. We have MAC addresses, IP addresses, and TCP/UDP port numbers… and low-level addresses are assigned to individual interfaces, not nodes.

Turns out that’s just one option… and not exactly the best one in many scenarios. You could have interfaces with no addresses, and you could have addresses associated with nodes, not interfaces.

In one of my introductory Segment Routing videos, I made claims along the lines of “Segment Routing totally simplifies the MPLS control plane, replacing LDP and local labels allocated to various prefixes with globally managed labels advertised in IGP”

It took two years for someone to realize the stupidity over-simplification of what I described. Matjaž Strauss sent me this kind summary of my errors:

You’re effectively claiming that SRGB has to be the same across all devices in the network. That’s not true; routers advertise SIDs and must configure label swap operations in case SRGBs don’t match.

Wait, what? What is SRGB and why could it be different across devices in the same network? Also, trust IETF to take a simple idea and complicate it to support vendor whims.

Azure and AWS have decent documentation (I always found it relatively easy to figure out what they’re doing), but what they implemented is sometimes so far away from what we’re used to that it’s hard to bridge the gap. Here’s how Olle Wilhelmsson solved that challenge:

Seventeen years after I started working on my EIGRP book, the reverse engineering days were over: RFC 7868 is the definitive guide to modern EIGRP (I’m not familiar with at least half of the concepts mentioned in it).

Just in case you’re interested in a bit of historical trivia:

• My EIGRP deciphering history started a few years before the book was published. In mid-1990s I was asked (as an external trainer) to create an EIGRP course for Cisco EMEA Training.
• I’ve never seen any internal EIGRP documentation or code – everything I knew about EIGRP I’ve learned from trying out crazy stuff and deciphering debugging messages.
• Two of the RFC authors (Russ White and Don Slice) were the technical reviewers for my EIGRP book. Russ copiously rewrote my pidgin English into something understandable – if you like reading my blog posts today, you should (also) thank Russ.

During my interview with David Bombal I made a recommendation I find crucial for anyone serious about blogging:

Make sure you own your content.

There’s a simple reason for that rule: if you want to write quality content, you’ll have to invest a lot of time into it.

TL&DR: If you want to test BGP, OSPF, IS-IS, or SR-MPLS in a virtual lab, you might build the lab faster with netsim-tools release 0.6.

In the netsim-tools release 0.6 I focused on adding routing protocol functionality:

• IS-IS on Cisco IOS/IOS XE, Cisco NX-OS, Arista EOS, FRR, and Junos.
• BGP on the same set of platforms, including support for multiple autonomous systems, EBGP, IBGP full mesh, IBGP with route reflectors, next-hop-self control, and BGP/IGP interaction.
• Segment Routing with MPLS on Cisco IOS XE and Arista EOS.

You’ll also get:

I know the title sounds like a buzzword-bingo-winning clickbait, but it’s true. Adrian Giacometti decided to merge the topics of two ipSpace.net online courses and automated deployment of AWS security rules using Terraform within GitLab CI pipeline, with Slack messages serving as manual checks and approvals.

Not only did he do a great job mastering- and gluing together so many diverse bits and pieces, he also documented the solution and published the source code:

• Part 1: Cloud & Network automation challenge: Deploy Security Rules in a DevOps/GitOps world with AWS, Terraform, GitLab CI, Slack, and Python (special guest FastAPI)
• Part 2: AWS, Terraform and FastAPI
• Part 3: GitLab CI, Slack, and Python
• Source code: aegiacometti/devops_cloud_challenge · GitLab

Want to build something similar? Join our Network Automation and/or Public Cloud course and get started. Need something similar in your environment? Adrian is an independent consultant and ready to work on your projects.