Automation Solution: Network Health State Report
How nice would it be to have a fabric health dashboard displaying a summary of numerous parameters you’re interested in (number of operational uplinks, number of BGP sessions…) for every switch in your fabric.
I’m positive you could hack something together using the customization capabilities of your favorite network management system… or you could write a simple data gathering solution like Stephen Harding did while attending the Building Network Automation Solutions online course.
VMware NSX Killed My EVPN Fabric
I had an interesting discussion with someone running VMware NSX on top of VXLAN+EVPN fabric a while ago. That’s a pretty common scenario considering:
- NSX’s insistence on having all VXLAN uplink from the same server in the same subnet;
- Data center switching vendors being on a lemming-like run praising EVPN+VXLAN;
- The reluctance of non-FAANG environments to connect a server to a single switch.
Apart from the weird times when someone started tons of new VMs, his fabric was running well.
The Cost of Disruptiveness and Guerrilla Marketing
A Docker networking rant coming from my good friend Marko Milivojević triggered a severe case of Deja-Moo, resulting in a flood of unpleasant memories caused by too-successful “disruptive” IT vendors.
Imagine you’re working for a startup creating a cool new product in the IT infrastructure space (if you have an oversized ego you would call yourself “disruptive thought leader” on your LinkedIn profile) but nobody is taking you seriously. How about some guerrilla warfare: advertising your product to people who hate the IT operations (today we’d call that Shadow IT).
Optimizing Environment Setup in Ansible Playbooks
Have you ever seen an Ansible playbook where 90% of the code prepares the environment, and then all the work is done in a few template and assemble modules? Here’s an alternative way of getting that done. Is it better? You tell me ;)
Worth Reading: Anycast DNS in Enterprise Networks
Anycast (advertising the same IP address from multiple servers/locations) has long been used to implement scale-out public DNS services (the whole root DNS system runs on massive anycast), but it’s not as common in enterprise networks.
The blog posts written by Tom Bowles should get you there. He started with the idea and described his implementation using Infoblox DNS.
Want to know even more? I covered numerous load balancing mechanisms including anycast in Data Centers Infrastructure for Networking Engineers webinar.
Redundant BGP Connectivity on a Single ISP Connection
A while ago Johannes Weber tweeted about an interesting challenge:
We want to advertise our AS and PI space over a single ISP connection. How would a setup look like with 2 Cisco routers, using them for hardware redundancy? Is this possible with only 1 neighboring to the ISP?
Hmm, so you have one cable and two router ports that you want to connect to that cable. There’s something wrong with this picture ;)
Network Automation Beyond Configuration Templating
Remember Nicky Davey describing how he got large DMVPN deployment back on track with configuration templating? In his own words…:
Configuration templating is still as big win a win for us as it was a year ago. We have since expanded the automation solution, and reading the old blog post makes me realise how far we have come. I began working with this particular customer in May 2017, so 2 years now. At that time the new WAN project was on the horizon and the approach to network configuration was entirely manual.
Here’s how far he got in the meantime:
New Content: Azure Networking and Automation Source-of-Truth
Last week I covered network security groups, application security groups and user-defined routes in the second live session of Azure Networking webinar.
We also had a great guest speaker on the Network Automation course: Damien Garros explained how he used central source-of-truth based on NetBox and Git to set up a network automation stack from the grounds up.
Recordings are already online; you’ll need Standard ipSpace.net Subscription to access the Azure Networking webinar, and Expert ipSpace.net Subscription to access Damien’s presentation. Azure Networking webinar is also part of our new Networking in Public Clouds online course.
Changing Cisco IOS BGP Policies Based on IP SLA Measurements
This is a guest blog post by Philippe Jounin, Senior Network Architect at Orange Business Services.
You could use track objects in Cisco IOS to track route reachability or metric, the status of an interface, or IP SLA compliance for a long time. Initially you could use them to implement reliable static routing (or even shut down a BGP session) or trigger EEM scripts. With a bit more work (and a few more EEM scripts) you could use object tracking to create time-dependent static routes.
Cisco IOS 15 has introduced Enhanced Object Tracking that allows first-hop router protocols like VRRP or HSRP to use tracking state to modify their behavior.
Networking in Public Clouds - New ipSpace.net Online Course
I have exciting news I’d love to share with you: we’re launching a new online course focused on networking in public clouds starting in February 2020 (I’ve been mulling over this idea and polishing the concept for almost 18 months, and finally it all came together ;)
With Go To The Cloud becoming the answer to all questions (regardless of what the question is), you can find tons of materials describing various aspects of public clouds, so you might wonder why I decided to enter the fray. The answer is simple: with everyone being focused on developers, there’s not much that an infrastructure engineer could use to help him survive when the developers move on and he’s left to manage whatever they put in place.
Worth Reading: Koding Academies
Every few weeks I stumble upon an article (or twitter storm) in which someone claims you don’t need formal education to get started as a Software Engineer (or whatever else) - all you need is a coding academy/bootcamp and you're all set.
George V. Neville-Neil wrote a hilarious rebuttal of this idea followed by some pretty good advice. Hope you’ll enjoy it as much as I did ;)
Worth Reading: SDN Ate My Hamster
A long while ago Daniel Dib wrote a nice blog post on “SDN will make the networking engineers obsolete” theme. While it sounds like beating a dead horse, the SDN craze isn’t subsiding, so another healthy dose of common sense might come handy.
Hint: if you’re not following Daniel’s blog, you should… even though he decided to make old farts’ life harder by publishing on LinkedIn.
Net2Text: Natural-Language Interface to Network Operations
Sick-and-tired of intent-based GUIs that are barely better than CiscoWorks on steroids? How about asking Siri-like assistant queries about network state in somewhat-limited English and getting replies back in full-blown sentences?
Warning: you might be reentering the land of unicorns driving flying DeLoreans... but then keep in mind what Arthur Clarke had to say on this topic ;).
Welcome to Net2Text, another proof-of-concept tool created by the group led by Laurent Vanbever… who joined us for a short chat to discuss it, resulting in Episode 105 of Software Gone Wild.
Automation Solution: Deploy BGP Routing with YANG Data Models
A while ago Ruben Tripiana tried to configure BGP on Cisco IOS using IETF YANG data models… and failed. In Spring 2019 Building Network Automation Solutions online course Chris Crook decided to deploy BGP routing on multiple platforms using YANG data models instead of configuration templates. Not only did he succeed, he also documented his work and the tools he used, and published the solution so you can replicate his efforts.
You can find many more network automation solutions created by the attendees of our automation course in solutions showcase.
Worth Following: Explaining Computer Things
People who can explain complex topics in simple terms, or focus on the essentials of a particular topic are exceedingly rare… and two of the best are Randall Munroe of the XKCD fame and Julia Evans, the mastermind behind WizardZines. I loved her recent curl and git exercises, and I’m guessing a lot of people in this industry would benefit from her latest HTTP zine.
Similarly to what I did a long time ago with ipSpace.net, Julia recently decided to go all-in, leaving her job and focusing on explaining things. I hope it will work out and we’ll keep enjoying her tidbits of wisdom for years to come.