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Internetworking perspectives by Ivan Pepelnjak
Updated: 2 min 48 sec ago

Troubleshooting VMware NSX on Software Gone Wild

January 29, 2015 - 11:03pm

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?

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Case Study: Combine Physical and Virtual Appliances in a Private Cloud

January 28, 2015 - 10:43pm

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.

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Is Controller-Based Networking More Reliable than Traditional Networking?

January 27, 2015 - 10:27pm

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?

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Video: IPv6 High Availability Components

January 26, 2015 - 10:07pm

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.

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IPv6 Renumbering – Mission Impossible?

January 25, 2015 - 10:34pm

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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Network Programmability 101: Q&A Time

January 22, 2015 - 10:16pm

In the last video from the Network Programmability webinar Matt Oswalt answered numerous questions from the audience.

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Lock-In Is Inevitable – Get Used to It!

January 20, 2015 - 10:44pm

For whatever reason (subliminal messages from vendor marketing departments?), I’m constantly brooding about the vendor lock-in, its inevitability, and the way supposedly disruptive companies try to use the fear of lock-in to persuade na├»ve customers to buy their products.

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vLAG Caveats in Brocade VCS Fabric

January 19, 2015 - 11:22pm

Brocade VCS fabric has one of the most flexible multichassis link aggregation group (LAG) implementation – you can terminate member links of an individual LAG on any four switches in the VCS fabric. Using that flexibility is not always a good idea.

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Improving ECMP Load Balancing with Flowlets

January 18, 2015 - 10:42pm

Every time I write about unequal traffic distribution across a link aggregation group (LAG, aka Etherchannel or Port Channel) or ECMP fabric, someone asks a simple question “is there no way to reshuffle the traffic to make it more balanced?

TL&DR summary: there are ways to do it, and some vendors already implemented them.

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SDN Router @ Spotify on Software Gone Wild

January 16, 2015 - 1:32am

Imagine you need a data center WAN edge router with multiple 10GE uplinks. You’d probably go for an ASR or a MX-series router, right? How about using a 2 Tbps ToR switch and an SDN solution to make it work with full Internet routing table?

If you happen to have iTunes on your computer, please spend 10 seconds rating the podcast before you start listening to it. Thank you!

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Should I Go For CCDE or VCIX-NV?

January 15, 2015 - 12:57am

I got a lengthy email from one of my readers a while ago, essentially asking a simple question: assuming I want to go return to my studies and move further than CCIE I currently hold, should I go for CCDE or the new VMware’s VCIX-NV?

Well, it’s almost like “do you believe in scale-up or scale-out?” ;) Both approaches have their merits.

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Scaling Overlay Virtual Networks: The Problem

January 13, 2015 - 11:33pm

Every major hypervisor and networking vendor has an overlay virtual networking solution. Obviously they’re not identical, and some of them work better than others in large-scale environments – an interesting challenge we tried to address in the Scaling Overlay Virtual Networks webinar. As always, we started by identifying the potential problems.

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Load Balancing Elephant Storage Flows

January 13, 2015 - 6:47am

Olivier Hault sent me an interesting challenge:

I cannot find any simple network-layer solution that would allow me to use total available bandwidth between a Hypervisor with multiple uplinks and a Network Attached Storage (NAS) box.

TL&DR summary: you cannot find it because there’s none.

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Network Programmability and SDN

January 11, 2015 - 10:51pm

What’s the difference between network programmability and SDN? Matt Oswalt explained his view on the topic in the Network Programmability 101 webinar.

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Pick a Topic for NSX Deep Dive Software Gone Wild Episode

January 10, 2015 - 1:07am

Dmitri Kalintsev, one of the networking guys from VMware NSX team, has kindly agreed to do an NSX technical deep dive Software Gone Wild episode… and you have the opportunity to tell him what you’d like to hear. It’s as easy as writing a comment, and we’ll pick one of the most popular topics.

Do keep in mind that we plan to do a technical deep dive, and it has to fit within an hour or so or nobody will ever listen to it, so please keep your suggestions focused. “Troubleshooting NSX”, “NSX Design”, or “NSX versus ACI ” is not what we’re looking for ;)

Palo Alto Virtual Firewalls on Software Gone Wild

January 9, 2015 - 12:25am

One of the interesting challenges in the Software-Defined Data Center world is the integration of network and security services with the compute infrastructure and network virtualization. Palo Alto claims to have tightly integrated their firewalls with VMware NSX and numerous cloud orchestration platforms - it was time to figure out how that’s done, so we decided to go on a field trip into the scary world of security.

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Latency: the Killer of Spread-Out Application Stack Ideas

January 8, 2015 - 2:59am

A few months ago I described how bandwidth limitations shatter the dreams of spread-out application stacks with elements residing (or being dynamically migrated) between data centers. Today let’s focus on bandwidth’s ugly cousin: latency.

TL&DR Summary: Spreading the server components of an application across multiple locations (multiple data centers or hybrid cloud deployments) can easily result in dismal performance even when there’s plenty of bandwidth available.

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How Does MPLS-TE Interact with QoS

January 7, 2015 - 12:24am

MPLS Traffic Engineer is sometimes promoted as a QoS solution (it seems bandwidth calendaring is a permanent obsession of some networking engineers, and OpenFlow is no more a solution than MPLS-TE was ;), but in reality it’s pretty hard to make the two work together seamlessly (just ask anyone who had to implement auto-bandwidth MPLS-TE in a large network).

Not surprisingly, we addressed the topic during our MPLS Tech Talk.

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Totally Redesigned Free Content Web Site

January 6, 2015 - 12:08am

One of the main complaints I was continuously getting about my free content is that there’s simply too much of it, and that it’s impossible to find what one is looking for.

New Year holidays gave me enough time to implement a project that has been on my to-do list for almost a year: total redesign of the free content web site. Feedback highly appreciated!

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