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Tom Limoncelli wrote a great article about starting an automation journey from sysadmin perspective. Not surprisingly, his recommendations aren’t that far off from what I’m telling networking engineers in my network automation presentations, Network Automation 101 webinar, and introductory part of Building Network Automation Solutions online course:
Read more ...Our good friend mr. Anonymous has too many buzzwords and opinions in his repertoire, at least based on this comment he left on my Using 4-byte AS Numbers with EVPN blog post:
But IGPs don't scale well (as you might have heard) except for RIFT and Openfabric. The others are trying to do ECMP based on BGP.
Should you be worried about OSPF or IS-IS scalability when building your data center fabric? Short answer: most probably not. Before diving into a lengthy explanation let's give our dear friend some homework.
Read more ...EVPN might be the next big thing in networking… or at least all the major networking vendors think so. It’s also a pretty complex technology still facing some interoperability challenges (I love to call it SIP of networking).
To make matters worse, EVPN can easily get even more confusing if you follow some convoluted designs propagated on the ‘net… and the best antidote to that is to invest time into understanding the fundamentals, and to slowly work through more complex scenarios after mastering the basics.
Read more ...I always wondered why it’s so hard to accept that someone might not find your preferred solution beautiful but would call it complex or even harmful (or from the other side, why someone could not possibly appreciate the beauty of your design)… and then stumbled upon this blog post by Scott Adams describing cognitive dissonance (the actual topic they’re discussing in the mentioned video doesn’t matter – look for the irrational behavior).
You might say “but we could politely agree to disagree” but unfortunately that implies that at least one of us is not fully rational due to Aumann’s Agreement Theorem.
More and more network devices support REST API as the configuration method. While it’s not as convenient as having a dedicated cmdlet, it’s possible to call REST API methods (and configure or monitor network devices) directly from a PowerShell script, as Mitja Robas demonstrated during the PowerShell for Networking Engineers webinar.
You’ll need at least free ipSpace.net subscription to watch the video.
This blog post was initially sent to the subscribers of my SDN and Network Automation mailing list. Subscribe here.
We’ve been told for years how we’re over-complicating networking, and how the software-defined or intent-based whatever will remove all that complexity and remove the need for networking engineers.
What never ceases to amaze me is how all these software-defined systems are demonstrated: each one has a fancy GUI that looks great in PowerPoint and might even work in practice assuming you’re doing exactly what they demonstrated… trying to be creative could result in interesting disasters.
Read more ...When the Spring 2018 Building Network Automation Solutions online course started, we didn’t know whether we’d run another course in 2018, so we offered engineers who wanted to get an early start Believer price.
The wait is over: the autumn 2018 course starts on September 18th. The schedule of the live sessions is already online, and we also have the first guest speakers. We’ll announce them in early June at which time you will no longer be able to get the Enthusiast price, so register ASAP.
A friend of mine who had the unfortunate “pleasure” of being exposed to one of the open-source controller platforms sent me this after reading my snarky take on bragging about what you’re doing at Something-Open-Something-Something conferences.
Read more ...After documenting the basic challenges of using EBGP and 4-byte AS numbers with EVPN automatic route targets, I asked my friends working for various vendors how their implementation solves these challenges. This is what Krzysztof Szarkowicz sent me on specifics of Junos implementation:
To learn more about EVPN technology and its use in data center fabrics, watch the EVPN Technical Deep Dive webinar.
Read more ...David Barroso was sick-and-tired of using ZX Spectrum of Network Automation and decided to create an alternative with similar functionality but a proper programming language instead of YAML dictionaries masquerading as one. The result: Brigade, an interesting network automation tool we discussed in Episode 90 of Software Gone Wild.
Notes:
Listening to the networking vendors it seems that zero-touch provisioning is a no-brainer … until you try to get it working in real life, and the device you want to auto-configure supports only IP address assignment via DHCP, configuration download via TFTP, and a DHCP option that points to the configuration file.
As Hans Verkerk discovered when he tried to implement zero-touch provisioning with Ansible while attending the Building Network Automation Solutions course you have to:
Read more ...After I posted the EVPN Route Target Considerations section of BGP in Data Center Fabrics document Lukas Krattiger pointed out another option available with Cisco Nexus-OS: it can rewrite ASN portion of EVPN Route Target in incoming EBGP updates. Updated version of the affected section is already online.
Not long after I published the blog post arguing against physical appliances, Oven wrote a very valid comment: "But then you'd have 20 individual systems to manage, add licenses to for additional features, updates etc."
Even though the blog post (and the comment) was written in 2013, not much has changed in the meantime.
Read more ...You probably know that fantastic feeling when you think your newly-discovered tool is a Hammer of Thor, capable of solving every problem (or at least crashing through it). I guess you’re also familiar with that sinking feeling when you’re trying to use your beloved hammer to whitewash a bikeshed.
Not surprisingly, the cruder the tool is, the quicker you’ll hit its limits, like when you try to do data processing in Jinja2 (hint: don’t).
Read more ...I was listening to very interesting Future of Networking with Fred Baker a long while ago and enjoyed Fred’s perspectives and historical insight, until unfortunately Greg Ferro couldn’t possibly resist the usual bashing of traditional routing protocols and praising of intent-based (or flow-based or SDN or…) whatever.
Here’s what I understood he said around 35:17
Read more ...A while ago Greg Ferro invited me for another fireside chat on Packet Pushers podcast. Hope you’ll enjoy our discussion.
The network automation evangelists love to tell you that automation is more than just device configuration management. They’re absolutely right… but it’s nonetheless amazing how much good you could do with simple tools solving simple problems.
Here’s what I got from Nicky Davey:
Read more ...Another month has swooshed by and it’s time for a refreshed list of upcoming webinars:
All you need to have to attend all these live sessions is a current ipSpace.net webinar subscription.
One of my friends sent me this question:
Do you remember if VLANs came first or was it VRFs?
I remember VLANs using ISL (pre-802.1q encapsulation) on early Cisco Ethernet switches (mid 90s), the earliest reference I could track down on Wikipedia is from 1988.
Read more ...Guess what I found: a software developer trying to persuade his peers that they need an API version of their CLI tool. Yes, I checked and it’s still 2018, and the year CLI dies seems to be a bit further out than some people thought.
I’d guess this proves that the rest of the world is not so far ahead of us lowly network engineers as blabbering pundits and vendor marketers would have us believe.
Needless to say, the engineers architecting Junos knew this almost 20 years ago.