Network designers (and smart consulting and system integration companies) often use ExpertExpress to get a second opinion on a design someone put together using technologies they’re not thoroughly familiar with. Not surprisingly, some of those third-party designs aren’t exactly optimal.

A while ago I was asked to review a data center “design” proposed to my customer by a system integrator. It had a pair of Nexus 5500 switches connecting servers and storage to a single Nexus 7000, which was then connected to WAN edge routers.

Brook Reams sent me an interesting tidbit: Brocade is the first vendor that actually shipped a VXLAN VTEP controlled by a VMware NSX controller. It’s amazing to see how Brocade leapfrogged everyone else (they also added tons of other new functionality in NOS releases 4.0 and 4.1).

Distributed DoS mitigation is another one of the “we were doing SDN without knowing it” cases: remote-triggered black holes are used by most major ISPs, and BGP Flowspec was available for years. Not surprisingly, people started using OpenFlow to implement the same concept (there’s even a proposal to integrate OpenFlow support into Bro IDS).

For more details, watch the Distributed DoS Prevention video recorded during the Real Life OpenFlow-based SDN Use Cases webinar.

During Interop 2014 I got involved in numerous interesting conversations revolving around SDN and new operations models (including the heretic idea of bundling appliances with application stacks and making developers responsible for network services).

During one of those discussions someone said “I think I get the ideas behind DevOps, but I don’t think we should configure our network devices with Puppet or Chef” to which I replied “Puppet or Chef are just tools, DevOps is a lifestyle.”

Paul Unbehagen made an interesting claim when presenting Avaya network built for Sochi Olympics during a recent Tech Field Day event: “we didn’t need MPLS or BGP to implement L2- and L3VPN. It was all done with SPB and IS-IS.”

Most ISPs rolling out large-scale residential IPv6 agree it’s a no-brainer, but the rest of the world still hesitates.

To help the dubious majority cross the (perceived) shaky bridge across the gaping chasm between IPv4 and IPv6, a team of great engineers with decades of IPv6 operational experience (including networking gurus from Time Warner, Comcast and Yahoo, and the never-tiring IPv6 evangelist Jan Žorž) wrote an IPv6 Troubleshooting for Helpdesks document.

When I first heard about NFV, I thought it was just another steaming pile of hype designed to push the appliance vendors to offer their solutions in VM format. After all, we’re past the hard technical challenges: most appliances deserve to have an Intel Inside sticker, performance problems have been addressed (see Intel DPDK, 6WIND, PF_ring and Snabb Switch), so what’s stopping us from deploying NFV apart from stubborn vendors who want to sell hardware, not licenses?

I always recommended EBGP-based designs for DMVPN networks due to the significant complexity of running IBGP without an underlying IGP. The neighbor next-hop-self all feature introduced in recent Cisco IOS releases has totally changed my perspective – it makes IBGP-over-DMVPN the best design option unless you want to use DMVPN network as a backup for MPLS/VPN network.

In the first half hour of the Infrastructure for Private Clouds workshop at last week’s Interop Las Vegas I focused on business aspects of private cloud design: defining the customers, the services, and the level of self-service you’ll offer to your customers.

Nick Martin published a great summary of these topics @ SearchServerVirtualization; I couldn’t have done it better myself (they want to get your email address, but this article is definitely worth it).

I had a nice chat with Doug Gourlay from Arista during the Interop Las Vegas and he made an interesting remark along the lines of “in leaf-and-spine fabrics it doesn’t make sense to use redundant supervisors in switches – they cause more problems than they solve.”

As always, in the end it all depends on your environment and use case, but he definitely has a point; good engineering always works better than a heap of kludges.