Load Balancing Elephant Storage Flows
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.
Read more ...Network Programmability and SDN
What’s the difference between network programmability and SDN? Matt Oswalt explained his view on the topic in the Network Programmability 101 webinar.
Pick a Topic for NSX Deep Dive Software Gone Wild Episode
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
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.
Read more ...Latency: the Killer of Spread-Out Application Stack Ideas
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.
Read more ...How Does MPLS-TE Interact with QoS
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.
Totally Redesigned Free Content Web Site
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!
BGP Deaggregation with Conditional Route Injection
Whenever there’s a weird request to do something totally illogical with BGP, there’s a knob in Cisco IOS to get it done (and increase the heartburn of CCIE candidates). Conditional Route Injection (the ability to insert more specific prefixes into BGP without having them in the IP routing table) is one of them.
Keep in mind: being a MacGyver is not a long-term strategy. Just because you can doesn’t mean that you should.
Read more ...That’s It for 2014
A dozen webinars, tens of public presentations and on-site workshops, numerous highly interesting ExpertExpress sessions, three books and over 250 blog posts. That should be enough for a year; it’s time to go offline.
I hope your company has a New Year freeze (and not let’s upgrade everything over New Year policy), so you’ll be able to do the same and enjoy some time during the rest of the year with your loved ones. See you in 2015!
MPLS Tech Talks: RSVP-TE 101
After discussing the basics of MPLS, MPLS-TE and LDP, and the relationship between FECs, LDP and BGP, Seamus and myself focused on another interesting topic: how MPLS protocol stack uses RSVP to implement traffic engineering.
VRF Lite on Nexus 5600
One of the networking engineers using my ExpertExpress to validate their network design had an interesting problem: he was building a multi-tenant VLAN-based private cloud architecture with each tenant having multiple subnets, and wanted to route within the tenant network as close to the VMs as possible (in the ToR switch).
He was using Nexus 5600 as the ToR switch, and although there’s conflicting information on the number of VRFs supported by that switch (verified topology: 25 VRFs, verified maximum: 1000 VRFs, configuration guide: 64 VRFs), he thought 25 VRFs (tenant routing domains) might be enough.
Read more ...Just Published: Scaling Overlay Virtual Networking Videos
The edited videos for Scaling Overlay Virtual Networking webinar are available on ipSpace.net Content site. Nuage Networks sponsored the webinar; the videos are thus publicly available (without registration).
Webinars in 2014, and a Quick Peek Into 2015
I promise engineers who renew their subscription 4-6 new webinars a year. It’s time to see whether I kept that promise in 2014.
TL&DR summary: it was a great year, but I still missed a few things.
Read more ...L2VPN over IPv6 with Snabb Switch on Software Gone Wild
Highly customizable high-speed virtual switch written in Lua sounds great, but is it really that easy to use? Simon Leinen was kind enough to get me in touch with Alex Gall, his colleague at Switch, who's working on an interesting project: implementing L2VPN over IPv6 with Snabb Switch.
Read more ...Facebook Next-Generation Fabric
Facebook published their next-generation data center architecture a few weeks ago, resulting in the expected “revolutionary approach to data center fabrics” echoes from the industry press and blogosphere.
In reality, they did a great engineering job using an interesting twist on pretty traditional multi-stage leaf-and-spine (or folded Clos) architecture.
Read more ...Performance Tests and Out-of-Box Performance
Simonp made a perfectly valid point in a comment to my latest OVS blog post:
Obviously the page you're referring to is a quick-and-dirty benchmark. If you wanted the optimal numbers, you would have to tune quite a few parameters just like for hardware benchmarks (sysctl kernel parameters, Jumbo frames, ...).
While he’s absolutely right, this is not the performance data a typical user should be looking for.
Read more ...Last Call: Overlay Virtual Networks in Software Defined Data Centers
If you want to get a free copy of my Overlay Virtual Networks in Software-Defined Data Centers book, download it now. The offer will expire by December 15th.
Just published: Enterprise IPv6 videos
The edited videos for my Enterprise IPv6 webinars have been published on my.ipspace.net. Enjoy!
Load Balancing in Google Network
Todd Hoff (of the HighScalability fame) sent me a link to an interesting video describing load-balancing mechanisms used at Google and how they evolved over time.
If the rest of the blog post feels like Latin, you SHOULD watch the Load Balancing and Scale-Out Application Architecture webinar.
The beginning of the story resembles traditional enterprise solutions:
Read more ...Scaling Distributed Systems Is Hard
Stumbled upon a hilarious description of challenges encountered when trying to scale distributed systems (cluster of controllers running centralized control plane comes to mind).
It starts with “If someone tells you that scaling out a distributed system is easy they are either lying or drunk, and possibly both,” and gets better and better. Enjoy!