
Author Archives: Ivan Pepelnjak
Author Archives: Ivan Pepelnjak
One of my readers sent me a simple question: “Do you plan to have a Python for Networking Engineers webinar?”
Short answer: no immediate plans.
Here are just a few reasons:
Read more ...Most network automation tutorials out there assume you’re running Ansible on your workstation and accessing virtual machines via SSH ports mapped by Vagrant. That’s great if you’re an experienced Ansible/Python user; for a clunky beginner like myself it’s safer to run Ansible within a VM that can be destroyed and recreated in seconds.
Another year swooshed by… it’s time for another what have we been doing in this year blog post.
Most important bit first: ipSpace.net is slowly morphing from a personal project into a (hopefully interesting) learning platform with almost 30 authors creating or participating in ipSpace.net webinars or online courses.
Read more ...During the Monitoring Software-Defined Networks webinar Terry Slattery addressed an interesting question: what happens if you run an SDN controller in a virtual machine and the virtual network crashes?
Want to know his take on the problem? Watch this free video on ipSpace.net content site.
I rarely get OpenFlow questions these days; here’s one I got not so long ago:
I've just spent the last 2 days of my life consuming the ONF 1.3.3 white paper in addition to the $vendor SDN guide to try and reconcile what features it does or does not support and have come away disappointed...
You’re not the only one ;)
Read more ...High-speed scale-out load balancing is a Mission Impossible. You can get the correct abstraction at the wrong cost or another layer of indirection (to paraphrase the authors of Fastly load balancing solution).
However, once every third blue moon you might get a team of smart engineers focused on optimal solutions to real-life problems. The result: a layer of misdirection, a combination of hardware ECMP and server-level traffic redirection. Enjoy!
The featured webinar in December 2016 is the Network Automation Tools webinar, and in the featured videos you'll find in-depth description of automation frameworks (focusing on Ansible) and open-source IPAM tools (including NSoT recently released by Dropbox).
To view the videos, log into my.ipspace.net, select the webinar from the first page, and watch the videos marked with star.
Read more ...In Software Gone Wild Episode 52 Katerina Barone-Adesi explained how Igalia implemented 4-over-6 tunnel termination (lwAFTR) with Snabb Switch. Their solution focused on very fast data plane and had no real control plane.
No problem – there are plenty of stable control planes on the market, all we need is some glue.
Read more ...I got several questions along the lines of “Do I need programming skills to attend the Building Network Automation Solutions course?”
Short answer: No.
Read more ...One of my readers designing a new data center fabric that has to provide L2 transport across the data center sent me this observation:
While we don’t have plans to seek an open solution in our DC we are considering ACI or VXLAN with EVPN. Our systems integrator partner expressed a view that VXLAN is still very new. Would you share that view?
Assuming he wants to stay with Cisco, what are the other options?
Read more ...On November 7th SDx Central published an article saying “OpenFlow is virtually dead.” There’s a first time for everything, and it’s a real fun reading a marketing blurb on a site sponsored by SDN vendors claiming the shiny SDN parade unicorn is dead.
On a more serious note, Tom Hollingsworth wrote a blog post in which he effectively said “OpenFlow is just a tool. Can we please find the right problem for it?”
Read more ...A few days after I published the blog post describing why it might make sense to attend the Building Network Automation Solutions course even when you’re already using a $vendor network management system/platform, I got a surprising email from one of my friends working for a major networking vendor:
Read more ...Dinesh Dutt was the guest speaker in the second Leaf-and-Spine Fabric Design session. After I explained how you can use ARP/ND information to build a layer-3-only data center fabric that still support IP address mobility Dinesh described the details of Cumulus Linux redistribute ARP functionality and demoed how it works in a live data center.
Got this comment to one of my L2-over-VXLAN blog posts:
I found the Avaya SPBM solution "right on the money" to build that L2+ fabric. Would you deploy Avaya SPBM?
Interestingly, I got that same question during one of the ExpertExpress engagements and here’s what I told that customer:
Read more ...My Network Automation in Enterprise Environments blog post generated the expected responses, including:
Some of the environments I am looking at have around 2000-3000 devices and 6-7 vendors for various functions and 15-20 different device platform from those vendors. I am trying to understand what all environments can Ansible scale up to and what would be an ideal environment enterprises should be looking at more enterprise grade automation/orchestration platforms while keeping in mind that platform allows extensibility.
Luckily I didn’t have to write a response – one of the readers did an excellent job:
Read more ...My friend Robert Turnšek published an interesting blog post pondering whether it makes sense to become a cloud provider.
I loved reading it, particularly the Trap for System Integrators part, because I know a bit of the history, and could easily identify two or three failed or stalled projects per paragraph (like: “Just adding some blade servers and storage to the existing server environment won’t make you a cloud provider”). Hope you’ll have as much fun as I did.
One of my readers was watching the Building Active-Active Data Centers webinar and sent me this question:
I'm wondering if you have additional info on how to address the ingress traffic flow issue? The egress is well explained but the ingress issue wasn't as well explained.
There’s a reason for that: there’s no good answer.
Read more ...A few weeks ago Matt Oswalt wrote an interesting blog post on principles of automation, and we quickly agreed it’s a nice starting point for a podcast episode.
In the meantime Matt moved to StackStorm team so that became the second focus of our chat… and then we figured out it would be great to bring in Matt Stone (the hero of Episode 13).
Read more ...Cisco VIRL is the ideal testing environment when you want to test your Ansible playbooks with various Cisco network operating systems (IOS, IOS XE, NX-OS or IOS XR). The “only” gotcha: how do you reach those devices from the outside world?
It was always possible to reach the management interface of devices running with VIRL, and it got even simpler with VIRL release 1.2.
Russ White wrote a great blog post about our failure to predict the future. The part I love most:
If the definition of insanity is doing the same things over and over again, each time expecting different results, what does that say about the world of network engineering?
Enjoy!