Ivan Pepelnjak
Author Archives: Ivan Pepelnjak
- Home → Author's archive:
Ivan Pepelnjak
A Burst of SDN Webinars (and a Slew of SDN Workshops)
You might have noticed that I’m running three SDN-related webinars in the next three weeks, which is the highest density of live webinar sessions I ever had. What’s going on?
Before moving on, I’d like to point out that the early bird pricing for our November SDN/SDDC retreat in Miami, Florida, ends on September 1st, and there are only a few tickets left. Time to register ;)
Read more ...Does Your Favorite Startup Support IPv6?
Whenever you talk to a new startup evaluating whether you’d consider including their products in your network, don’t forget to ask them a fundamental question: “does your product support IPv6?”
If they reply “Nobody has ever asked for it”, it’s time to turn around and run away.
Read more ...Enterprise IPv6 Adoption Explained
The OSCON keynote by Simon Wardley explains a number of things, including (lack of) enterprise IPv6 adoption. Enjoy!Video: What Is Cumulus Linux All About?
In May 2015 I invited Dinesh Dutt to talk about Cumulus Linux and its typical use cases on an update session of the Data Center Fabrics Architecture webinar.
As expected, he started with the big picture: what is Cumulus Networks and Cumulus Linux all about?
SDN Will Not Solve Real-Life Enterprise Problems
It’s hard to visit an IT journal web site without stumbling upon an SDN fairy tale. Here’s another one:
The idea is to cut away the manual process of setting up new firewalls, load balancers and other network appliances, and instead open the door to provisioning a new network infrastructure within a few minutes.
And why exactly is it that you can’t do that today?
Read more ...IPv6 and the Swinging Technology Pendulum
35 years ago, mainframes, single-protocol networks (be it SNA or DECnet), and centralized architectures that would make hard-core SDN evangelists gloat with unbridled pride were all the rage. If you’re old enough to remember IBM SNA, you know what I’m talking about.
A few years later, everything changed.
Read more ...Published: Designing Scalable Web Applications (Part 2)
I published the second part of my Designing Scalable Web Applications course on my free content web site.
These presentations focus more on the application-level technologies (client- and server side), but I’m positive you’ll find some useful content in the caching and scale-out applications with load balancing sections.
SDN, SD-WAN and FCoE on Gartner Networking Hype Cycle
Gartner has updated their networking hype cycle. Not surprisingly:
- Ethernet switching fabrics are on the slope of enlightenment (finally – we’ve been educating networking engineers on what they really are for half a decade);
- SDN is well on its way into the trough of disillusionment (shameless plug: I guess not enough people attended real-life SDN workshops) and whitebox switching is going the same way;
- SD-WAN is nearing the peak of inflated expectations;
- FCoE and Long-Distance vMotion will be dead before they reach the plateau.
Gartner won’t give you free access to the graph, but you’ll find it in an article published on The Register.
Can Virtual Routers Compete with Physical Hardware?
One of the participants of the Carrier Ethernet LinkedIn group asked a great question:
When we install a virtual-router of any vendor over an ordinary sever (having general-purpose microprocessor), can it really compete with a physical-router having ASICs, Network Processors…?
Short answer: No … and here’s my longer answer (cross-posted to my blog because not all of my readers participate in that group).
Read more ...Video: Overview of IPv6 First-Hop Security Challenges
Like all other ipSpace.net webinars, the IPv6 Microsegmentation webinar starts with a brief description of the problem we’re trying to solve: the IPv6 first-hop security challenges.
For an overview of this problem, watch this free video from the IPv6 microsegmentation webinar, for more details, watch the IPv6 Security webinar.
Big Flowering Things and Lego Bricks
Matt Oswalt wrote a great blog post complaining about vendors launching ocean-boiling solutions instead of focused reusable components, and one of the comments his opinion generated was along the lines of “I thought one of the reasons people wanted SDN, is because they wanted to deal with The Network – think about The Network's Performance, Robustness and Services instead of dealing with 100s or 1000s of individual boxes.”
The comment is obviously totally valid, so let me try to reiterate what Matt wrote using Lego bricks ;)
Read more ...Published: New SDN and NFV Materials
Last week I published slide decks for Network Function Virtualization, BGP-Based SDN Solutions and SDN Use Cases webinars – they’re available to subscribers and attendees registered for individual webinars.
Content from all three webinars is part of my SDN workshop – if you’d like to hear a live explanation, register for one of them.
Video: What Is IPv6?
One of the topics I’m addressing in the Enterprise IPv6 101 webinar (after all, it’s an introductory-level webinar) is the question of “what exactly is IPv6”. After all the promises, myths, in the end it turns out all we got were bigger addresses (and ton of additional complexity).
Fat Fingers and Other Campfire Stories
A recent well-publicized network outage prompted someone to start collecting fat-finger horror stories, and dozens of networking engineers were quick to chime in. Enjoy!
Reliability of SD-WAN and Hybrid WAN Solutions
My Business Case for SD-WAN blog post received numerous comments pointing out the potential pitfalls of hybrid WAN, including reduced security, unreliable Internet services and denial-of-service attacks.
While all those comments are perfectly valid, I still think hybrid WAN (whether implemented with traditional technologies or SD-WAN products) makes perfect sense.
Read more ...Explaining the Pervasive Kludgeitis
I found a great explanation for hodgepodge of kludges found in "organically grown" solutions (legacy precursors to SD-WAN come to mind):
In a long-lived project, components are being replaced. Nice reusable components are easy to replace and so they are. Ugly non-reusable components are pain to replace and each replacement means both a considerable risk and considerable cost. Thus, more often then not, they are not replaced. As the years go by, reusable components pass away and only the hairy ones remain. In the end the project turns into a monolithic cluster of ugly components melted one into another.
Note: You really should read the whole blog post.
Must read: Big Flowering Thing
It's so nice to see someone saying eloquently what you've been trying to say for a while – you (RFC 2119) MUST read what my friend Matt Oswalt wrote about Big Flowering Things.
Explaining the Mysteries of WiFi and Internet ;)
“Daddy, why is Internet not working even though I have good signal?”
“You really want to know?”
“Sure”
“OK, let me draw a diagram or two ;)”
… and now my 8-year old knows how DHCP and DNS works (root cause was a broken DNS proxy running on upstream $0.99 WAN router).
Can You Avoid Networking Software Bugs?
One of my readers sent me an interesting reliability design question. It all started with a catastrophic WAN failure:
Once a particular volume of encrypted traffic was reached the data center WAN edge router crashed, and then the backup router took over, which also crashed. The traffic then failed over to the second DC, and you can guess what happened then...
Obviously they’re now trying to redesign the network to avoid such failures.
Read more ...Interested in Mesh Wireless Networks?
Engineers developing open-source wireless mesh network protocols and solutions get together every now and then to test the performance of competing mesh network ideas.
The next conference is organized in August 2015 in Maribor, Slovenia, so if you ever needed a good excuse to drop by Slovenia, now you have one ;)