Numerous marketers and SDN/OpenFlow pundits keep repeating how they’ll save the (networking) world and bring true nirvana to the network operations with their flashy new gadgets. Nothing can be further from the truth because we cannot get rid of the legacy permeating the whole TCP/IP stack, as I explained in this post written in July 2013.

Note: Joe was obliquely touting the benefits of what became Cisco ACI versus the “more traditional” implementations like VMware NSX. While Cisco ACI does have an interesting architecture, that architecture is too complex for many deployments, and ACI often gets used as a centralized VLAN provisioning tool.

Where’s the Revolutionary Networking Innovation?

In his recent blog post Joe Onisick wrote “What network virtualization doesn’t provide, in any form, is a change to the model we use to deploy networks and support applications. [...] All of the same broken or misused methodologies are carried forward. [...] Faithful replication of today’s networking challenges as virtual machines with encapsulation tunnels doesn’t move the bar for deploying applications.

Much as I agree with him, we can’t change much on planet Earth due to the fact that VMs use Ethernet NICs (so we need some form of VLANs to cater to infinite creativity of some people), IP addresses (so we need L3 forwarding), broken TCP stack (requiring load balancers to fix it), and obviously can’t be relied upon to be sufficiently protected (so we need external firewalls). Furthermore, unless we manage to stop shifting the problems around, the networking as a whole won’t get simpler.

What overlay network virtualization does bring us is a decoupling that makes physical infrastructure less complex so it can focus on packet forwarding instead of zillions of customer-specific features preferably baked in custom ASICs. Obviously that’s not a good thing for everyone out there.

It could also be that the company Joe is currently working for1 has some truly revolutionary ideas (or so their web page claims), and I would love to be proven wrong, but the first glimpses weren’t exactly encouraging.

  1. Joe was working in Insieme marketing at that time. Insieme was acquired by Cisco, and their product became the first version of Cisco ACI. ↩︎

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  1. Hi Ivan,

    I just had a flashback of years of debugging networks to solve poor application performance. Just like overlay proponents stress the point that if you design and scale your underlay, your overlay will have less/none to worry about, so did the developers for their apps assuming that various network conditions are not an issue to be concerned about. Both can be viewed as decoupling... Why do we not want to learn from the past mistakes?

    I agree that decoupling can bring lots of value, but when decoupling leads of obscurity, you are just inviting problems.

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