I’m not the only one telling people not to bet the farm on Santa Claus and dancing unicorns. Pete Welcher wrote a nice blog post describing the implications of laws of physics and data gravity (I described the gory details in Designing Active-Active Data Centers and AWS Networking Deep Dive webinars).
Meanwhile, Russ White reviewed an article that (without admitting it) discovered that serverless is just software running on other people’s servers.
Enjoy!
Every now and then I get a question along the lines of I’m your subscriber and would like to know more about X, so I decided to start creating technology-specific pages on www.ipSpace.net that would include links to most relevant ipSpace.net blog posts, webinars, sections in our online courses, and interesting third-party resources.
The subscriber triggering this process asked me about Intent-Based Networking, so here’s the relevant resources page.
A long while ago I published a sample Ansible/NAPALM/Jinja2 solution that would take LLDP information and turn it into a network diagram (I described its details in a short video that’s accessible to anyone attending our network automation course or having an Expert subscription).
The trickiest part of that solution was detection of bidirectional links:
Read more ...When I started working with Cisco routers in late 1980s all you could get were devices with a dozen or so ports, and CPU-based forwarding (marketers would call it software defined these days). Not surprisingly, many presentations in Cisco conferences (before they were called Networkers or Cisco Live) focused on good network design and split of functionality in core, aggregation (or distribution) and access layer.
What you got following those rules were stable and predictable networks. Not everyone would listen; some customers tried to be cheap and implement too many things on the same box… with predictable results (today they would be quick to blame vendor’s poor software quality).
Read more ...This blog post was initially sent to subscribers of my SDN and Network Automation mailing list. Subscribe here.
One of my readers sent me this question:
Would you write about methods for reverting from expected new state to old state in the case automation went wrong due to (un)predictable events that left a node or network in a limbo state betwixt and between.
Like always, there’s the easy and the really hard part.
Read more ...Last Thursday I started another experiment: a series of live webinar sessions focused on business aspects of networking technologies. The first session expanded on the idea of three paths of enterprise IT. It covered the commoditization of IT and networking in particular, vendor landscape, various attempts at segmenting customers, and potential long-term Enterprise IT paths. Recording is already online and currently available with standard subscription.
Although the attendance was lower than usual, attendees thoroughly enjoyed it – one of them sent me this: “the value of ipSpace.net is that you cut through the BS”. Mission accomplished ;)
If you're at least vaguely familiar with modern black hole theories, you'll totally enjoy the concept of email event horizon.
A while ago I made a statement along the lines of “MPLS segment routing is the best thing that happened to MPLS control plane in a decade”. Obviously some MPLS-focused engineers disagree with that and a few years ago I decided to write a lengthy blog post explaining the differences between using MPLS SR with IGP (or BGP) versus more traditional IGP+LDP approach.
Obviously, I wasn’t making any progress on that front, so the only way forward was to record a short video on the topic which didn’t work well either because the end-result was a set of three videos (available with free or paid ipSpace.net subscription).
When I started working with Ansible networking modules they had a distinct science fair feel: everything was in flux, every new version of Ansible would break my playbooks, modules would disappear from one release to next, documentation was sketchy and describing the latest development code not a shipped release.
In the meantime, code, documentation, and release/deprecation management improved dramatically:
Read more ...Last year I got into somewhat-heated discussion with a few engineers who followed the advice to run IBGP EVPN address family on top of an EBGP underlay.
My main argument was simple: this is not how BGP was designed and how it’s commonly used, and twisting it this way requires schizophrenic BGP routing process which introduces unnecessary complexity (even though it looks simple in Junos configuration) and might confuse people who have to run the network after the brilliant designer is gone.
Read more ...This is a guest blog post by Andrea Dainese, senior network and security architect, and author of UNetLab (now EVE-NG) and Route Reflector Labs. These days you’ll find him busy automating Cisco ACI deployments.
Following the Ivan’s post about Firewall Ruleset Automation, I decided to take a step forward: can we always have up-to-date and clean firewall policies without stale rules?
We usually configure and manage firewalls using a process like this:
Read more ...In April 2019 we’re starting a new cloud security saga with Matthias Luft. The first webinar in this series will focus on the basics, subsequent live sessions spread through the rest of 2019 will cover individual technologies.
Another series we’re starting is Business Aspects of Networking, opening on April 4th with Three Paths of Enterprise IT.
We’ll also continue the math-in-networking series, this time focused on reliability functions and advanced reliability topics.
A few weeks ago, I had an interesting video chat with David Bombal in which we covered a wide variety of topics including
Note: David posted the whole list of topics with timestamps in the pinned comment under the video.
An attendee of our Building Network Automation Solutions online course decided to automate his NSX-T environment and sent me this question:
I will be working on NSX-T quite a lot these days and I was wondering how could I automate my workflow (lab + production) to produce a certain consistency in my work.
I’ve seen that VMware relies a lot on PowerShell and I’ve haven’t invested a lot in that yet … and I would like to get more skills and become more proficient using Python right now.
Always select the most convenient tool for the job, and regardless of personal preferences PowerShell seems to be the one to use in this case.
Read more ...If you’ve been in networking long enough you’d probably noticed an interesting pattern:
I was reminded of this pattern when I was explaining the traffic filtering measures available in private and public clouds during the Designing Infrastructure for Private Clouds workshop.
Read more ...Chris Crook decided to work on a pretty typical problem for his second hands-on assignment in the Building Network Automation Solutions online course: create a network diagram from adjacency data.
He decided to rely on BGP adjacencies (I would usually use LLDP) and added an interesting twist: instead of Ansible he used Nornir with NAPALM.
Read more ...Spring started for real, so it was time for some early-spring cleaning and I managed to complete two webinars during last week:
Both webinars are part of standard ipSpace.net subscription
If you’re a BGP newbie, you’ll love this BGP Show and Tell series from Denise Fishburne. Enjoy!
I mentioned Multipath TCP (MP-TCP) numerous times in the past but I never managed to get beyond “this is the thing that might solve some TCP multihoming challenges” We fixed this omission in Episode 100 of Software Gone Wild with Christoph Paasch (software engineer @ Apple) and Mat Martineau from Open Source Technology Center @ Intel.
Read more ...Remember the previous blog post in this sequence in which I explained the need for single source-of-truth used in your network automation solution? No? Please read it first ;)
Ready for the next step? Assuming your sole source-of-truth is the actual device configuration, is there a magic mechanism we can use to transform it into something we could use in network automation?
TL&DR: No.
Read more ...