A few weeks ago, Daniel posted a piece about using different underlay and overlay protocols in a data center fabric. He says:
There is nothing wrong with running BGP in the overlay but I oppose to the argument of it being simpler.
One of the major problems we often face in network engineering—and engineering more broadly—is confusing that which is simple with that which has lower complexity. Simpler things are not always less complex. Let me give you a few examples, all of which are going to be controversial.
Way in the past, the EIGRP team (including me) had an interesting idea–why not aggregate routes automatically as much as possible, along classless bounds, and then deaggregate routes when we could detect some failure was causing a routing black hole? To understand this concept better, consider the network below.
Engineers (and marketing folks) love new technology. Watching an engineer learn or unwrap some new technology is like watching a dog chase a squirrel—the point is not to catch the squirrel, it’s just that the chase is really fun. Join Andrew Wertkin (from BlueCat Networks), Tom Ammon, and Russ White as we discuss the importance of simple, boring technologies, and moderating our love of the new.
What is the first thing almost every training course in routing protocols begin with? Building adjacencies. What is considered the “deep stuff” in routing protocols? Knowing packet formats and processes down to the bit level. What is considered the place where the rubber meets the road? How to configure the protocol.
I’m not trying to cast aspersions at widely available training, but I sense we have this all wrong—and this is a sense I’ve had ever since my first book was released in 1999. It’s always hard for me to put my finger on why I consider this way of thinking about network engineering less-than-optimal, or why we approach training this way.
Recent research into the text of RFCs versus the security of the protocols described came to this conclusion—
One of the big movements in the networking world is disaggregation—splitting the control plane and other applications that make the network “go” from the hardware and the network operating system. This is, in fact, one of the movements I’ve been arguing in favor of for many years—and I’m not about to change my perspective on the topic.
Back in January, I ran into an interesting article called The many lies about reducing complexity:
Reducing complexity sells. Especially managers in IT are sensitive to it as complexity generally is their biggest headache. Hence, in IT, people are in a perennial fight to make the complexity bearable.
Why are networks so insecure?
One reason is we don’t take network security seriously. We just don’t think of the network as a serious target of attack. Or we think of security as a problem “over there,” something that exists in the application realm, that needs to be solved by application developers. Or we think the consequences of a network security breach as “well, they can DDoS us, and then we can figure out how to move load around, so if we build with resilience (enough redundancy) we’re already taking care of our security issues.” Or we put our trust in the firewall, which sits there like some magic box solving all our problems.
What percentage of business-impacting application outages are caused by networks? According to a recent survey by the Uptime Institute, about 30% of the 300 operators they surveyed, 29% have experienced network related outages in the last three years—the highest percentage of causes for IT failures across the period.
A secondary question on the survey attempted to “dig a little deeper” to understand the reasons for network failure; the chart below shows the result.
Crossing from the domain of test pilots to the domain of network engineering might seem like a large leap indeed—but user interfaces and their tradeoffs are common across physical and virtual spaces. Brian Keys, Eyvonne Sharp, Tom Ammon, and Russ White as we start with user interfaces and move into a wider discussion around attitudes and beliefs in the network engineering world.