Ivan Pepelnjak
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Ivan Pepelnjak
Myths That Refuse to Die: Scalability of Overlay Virtual Networking
If you watched the Network Field Day videos, you might have noticed an interesting (somewhat one-sided) argument I had with Sunay Tripathi, CTO and co-founder of Pluribus Networks (start watching at around 32:00 to get the context). Let’s try to get the record straight.
Read more ...Must bookmark: NSX Link-o-Rama
Brad Hedlund sent me a link to a fantastic list of NSX resources, from design and troubleshooting guides to videos and blog posts. A must-bookmark page if you're even remotely interested in VMware NSX.Networking Field Day 9: Brief Recap
I’m sitting in the San Francisco airport with nothing better to do than writing blog posts, so let’s see what we’ve seen and learned during the Networking Field Day 9.
Most videos recorded during the week are already online. You’ll find links to them in the Presentation Calendar section.
Read more ...Hands-On Tail-F Experience on Software Gone Wild
Tail-F NCS implements one of the most realistic approaches to service abstraction (the cornerstone of SDN – at least in my humble opinion) – an orchestration system that automates service provisioning on existing infrastructure.
Is the product really as good as everyone claims? How hard is it to use? How steep is the learning curve? Boštjan Šuštar and Marko Tišler from NIL Data Communications have months of hands-on experience and were willing to share it in Episode 22 of Software Gone Wild.
Per-Packet Load Balancing on WAN links
One of my readers got an interesting idea: he’s trying to make the most of his WAN links by doing per-packet load balancing between a 30 Mbps and a 50 Mbps link. Not exactly surprisingly, the results are not what he expected.
Read more ...ONS Accelerate Workshop: Amazingly Refreshing
Sometimes the stars do align: Open Networking Summit organized their Service Provider Accelerate Workshop just a day prior to Network Field Day, so I had the fantastic opportunity to attend both.
I didn’t know what to expect from an event full of SDN/NFV thought leaders, and was extremely pleasantly surprised by the amount of realistic down-to-earth information I got.
Read more ...Whitebox Switching and Industry Pundits
Industry press, networking blogs, vendor marketing whitepapers and analyst reports are full of grandiose claims of benefits of whitebox switching and hardware disaggregation. Do you ever wonder whether these people actually practice their theories?
Read more ...Scaling Overlay Networks: Distributed Data Plane
“Thou Shalt Have No Chokepoints” is one of those simple scalability rules that are pretty hard to implement in real-life products. In the Distributed Data Plane part of Scaling Overlay Networks webinar I listed data plane components that can be easily distributed (layer-2 and layer-3 switching), some that are harder to implement but still doable (firewalling) and a few that are close to mission-impossible (NAT and load balancing).
Let’s Meet in Zurich or Heidelberg
I’ll be speaking at two conferences in March: SDN event in Zurich organized by fantastic Gabi Gerber, and the best boutique security conference – Troopers 15 in Heidelberg. If you’ll be attending one of these events, just grab me, drag me to the nearest coffee table, and throw some interesting questions my way ;) … and if you happen to be near one of these locations, let me know and we might figure out how to meet somewhere.
Read more ...Whiteboarding Cisco ACI on Software Gone Wild
Late last year David Gee and I wanted to test another interesting gizmo: an online virtual whiteboard. David was pondering some interesting aspect of Cisco ACI and they seemed like a perfect topic for an impromptu discussion.
Read more ...We Need to Move from Assembling Car Parts to Driving Cars
During a great conversation I had with Terry Slattery during Interop New York, he said “well, I don’t think anyone should be configuring VLANs and asking ÔÇśHow to configure a VLAN on a switch’ – we should be focused on providing end-to-end connectivity”, and there’s absolutely nothing in that statement that one could disagree with.
Read more ...Combining MPLS/VPN, MPLS-TE and QoS on MPLS Talks
In the final part of our MPLS-focused discussion, Seamus wanted to know how one could combine MPLS/VPN, MPLS-TE and QoS (for example, sending VoIP traffic for one customer over a different path).
Short answer: don’t even think about doing that. The added complexity is not worth whatever extra money you’ll be charging the customer (or not).
Before Talking about vMotion across Continents, Read This
I expect to hear a lot about the “wonderful” idea of moving running VMs 100 msec away (across the continent) in the upcoming weeks. I would recommend you read a few of my older blog posts before considering it… and don’t waste time trying to persuade the true believers with technical arguments – talk with whoever will foot the bill or walk away.
Read more ...Big Cloud Fabric: Scaling OpenFlow Fabric
I’m still convinced that architectures with centralized control planes (and that includes solutions relying on OpenFlow controllers) cannot scale. On the other hand, Big Switch Networks is shipping Big Cloud Fabric, and they claim they solved the problem. Obviously I wanted to figure out what’s going on and Andy Shaw and Rob Sherwood were kind enough to explain the interesting details of their solution.
Long story short: Big Switch Networks significantly extended OpenFlow.
Read more ...Last Chapter of Data Center Design Case Studies Is Published
A few days ago I completed the last chapter in the Data Center Design Case Studies book: building disaster recovery and active-active data centers. It focuses on application behavior and business needs, not on the underlying technologies; the networking technology part tends to be way easier to solve than the oft-ignored application-level challenges.
Troubleshooting VMware NSX on Software Gone Wild
When we started planning a VMware NSX-focused podcast episode with Dmitri Kalintsev, I asked my readers what topics they’d like to see covered. Two comments that we really liked were “how do I get started with VMware NSX?” and “how do I troubleshoot this stuff?”
Read more ...Case Study: Combine Physical and Virtual Appliances in a Private Cloud
Cloud builders are often using my ExpertExpress service to validate their designs. Tenant onboarding into a multi-tenant (private or public) cloud infrastructure is a common problem, and tenants frequently want to retain the existing network services appliances (firewalls and load balancers).
The Combine Physical and Virtual Appliances in a Private Cloud case study describes a typical solution that combines per-tenant virtual appliances with frontend physical appliances.
Is Controller-Based Networking More Reliable than Traditional Networking?
Listening to some SDN pundits one gets an impression that SDN brings peace to Earth, solves all networking problems and makes networking engineers obsolete.
Cynical jokes aside, and ignoring inevitable bugs, is controller-based networking really more reliable than what we do today?
Read more ...Video: IPv6 High Availability Components
Last spring I ran an IPv6 High Availability webinar which started (not surprisingly) with a simple question: “which network components affect availability in IPv6 world, and how is a dual-stack or an IPv6-only environment different from what we had in the IPv4 world?”
This part of the webinar is now available on ipSpace.net content web site. Enjoy the video, explore other IPv6 resources on ipSpace net, and if you’re from Europe don’t forget to register for the IPv6 Security Summit @ Troppers in mid-March.
IPv6 Renumbering – Mission Impossible?
In one of the discussions on v6ops mailing list Matthew Petach wrote:
The probability of us figuring out how to scale the routing table to handle 40 billion prefixes is orders of magnitude more likely than solving the headaches associated with dynamic host renumbering. That ship has done gone and sailed, hit the proverbial iceberg, and is gathering barnacles at the bottom of the ocean.
Is it really that bad? Is simple renumbering in IPv6 world just another myth? It depends.
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