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Hitchhiker’s Guide to onePK

Cisco Live Milan is around the corner and I’m getting my session, The Hitchhiker’s Guide to onePK, ready for it’s European debut.  While it’s lovely to be in the CiscoLive Distinguished Speaker Hall of Fame, putting a good presentation together hasn’t gotten any easier.  The hard questions still need to be asked:  Do I have too many slides?  Have I crossed the line between technical and boring?  Will the demos work?  Will anyone laugh at my jokes?

And perhaps most importantly for this session: does anyone read Douglas Adams any more?

Here’s why.  I borrowed the title of Douglas Adam’s iconic Hitchhiker’s Guide to the Galaxy for good reason.  The original Hitchhiker’s Guide follows an ordinary guy, Arthur Dent, as he is unwillingly dragged into an intra-galactic adventure, with little more than the Guide, a pint of beer and a packet of peanuts to see him through.  Faced with the vast and confusing world of Software Defined Networking (SDN) and programmability, network engineers are in a position to know exactly how Arthur Dent felt.  New buzzwords, emerging standards, an abundance of marketing slides with vague but brightly colored blobs, and a lot of talk about programming languages can be disorienting to the best of us.

Enter the Hitchhiker’s Guide to onePK.

Notice that I did not call my session the Hitchhiker’s Guide to SDN.  SDN calls for more of an Encyclopedia Galactica than a Hitchhiker’s Guide, if you know what I mean.  Instead, my aim is to take a deep dive into one aspect of network programmability that network engineers can really relate to: onePK. Read More »

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Autonomic Networking – From Theory to Practice

Autonomic Networking is well understood in theory, but real, consistent and extensible implementations don’t exist. In this post I suggest a reason for the lack in execution, and our vision to provide a working, implementable Autonomic Networking Architecture.

Wipe off the dust…

When asking a researcher about autonomic systems, (s)he might blow the dust off a stack of papers, or proudly pull a couple of old books off his shelf. Or point to IBM’s IEEE paper from 2003. From a research perspective, autonomics is well understood. It’s this self-management thing, with all those self-* properties. Self-configuration and self-optimisation for example. Distribution, control loops, and so on. Even the Wikipedia articles are written. So, we’re done, aren’t we?

No we’re not.

Ask your friendly neighbourhood network engineers about Autonomic Networking. The one that proudly hacks expect scripts at night to make his admin database talk to his routers. Or the front line engineer who applies a network service class to one of his customers. Likely, both of them would look at you with big eyes, and after explaining that the network manages itself, intelligently, you’d hear back: “That’s like Skynet, isn’t it?”

No it’s not. Read More »

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Extending Zeroconf Services: Cache Tuning

Introduction

With the introduction of Cisco mDNS Service Discovery Gateway in IOS, customers that have implemented the solution are observing client behavior they haven’t seen prior to extending services across subnet boundaries. One of the effects is the duplicate name issue seen when devices with enabled services are moved from one L3 subnet to another L3 subnet and these two subnets happen to be connected to the same router/switch running the Service Discovery Gateway (SDG).

Background

When devices (like a Mac OS X computer) offer a service such as Remote Login (SSH) or Screen Sharing (VNC), they will announce these services using mDNS/Bonjour/Zeroconf using their hostname as configured in ‘System Preferences -> Sharing -> Computer Name’ (see Fig. 1).
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Cisco Service Discovery Gateway – Enabling Zeroconf in Enterprise Networks

Cisco Service Discovery Gateway – Enabling Zeroconf in Enterprise Networks

I’ll admit it: I’m what others call an Apple fan boy. One of the many reasons for being one is the polished user experience and the ease-of-use of their products. One of the underlying technologies that enables the user to discover devices and services on the network is Zeroconf or, as Apple calls it, Bonjour.

Zeroconf consists of three major components:

  • Address auto configuration,
  • Naming –and–
  • Service discovery.

If your network doesn’t have a DHCP server or you haven’t statically assigned an IP address to your host, most operating systems will use an automatic private IP address. I’m not going into much detail on address auto configuration except that this is typically done using a technique called APIPA (Automatic Private IP Addressing) for IPv4 the host will use the famous 169.254.0.0/16 addresses or, in case of IPv6, by using link-local addresses only (FE80::/10) which has been designed into IPv6 as a basic functionality from day one. Also, naming is not of much of a concern in the context of this discussion. However, it is worth mentioning that Zeroconf names can contain Unicode characters and whitespace, which can make those names a lot more user friendly and meaningful contrary to pure DNS names.

The more interesting part, as it pertains to Zeroconf, is the service discovery. Read More »

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Route Redistribution – A thing of the past?

July 2, 2013 at 11:21 am PST

This week at CiscoLive Orlando, Cisco made two announcements around Enterprise Routing -- Open EIGRP and EIGRP OTP. Originally announced at CiscoLive London, EIGRP has been opened to the community as an IETF Informational Draft “Open EIGRP”, Open EIGRP  provides vendors with technical information on EIGRP and the accumulation of 20 years of development and enhancements. With the publishing of this IETF Draft, vendors can now integrate EIGRP into their appliances and interop with Cisco.

On Tuesday, Cisco also announced a new innovation in Enterprise Routing; “EIGRP Over the Top” (or simply OTP).

EIGRP OTP

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