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 ...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 ...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 ...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).
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 ...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 ...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.
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 ...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.
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 ...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.
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.
Read more ...In the last video from the Network Programmability webinar Matt Oswalt answered numerous questions from the audience.
Load sharing in MPLS networks is always an interesting topic, and we couldn’t possibly avoid it during our MPLS-focused Tech Talks – watch the video.
After discussing the load sharing intricacies we briefly dabbled with the concept of entropy labels.
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.
Read more ...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.
2015-01-23: Added a few caveats on load distribution
Read more ...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.
Read more ...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!
Read more ...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.
Read more ...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.