To become a CCIE you need detailed knowledge of OSPF. Most candidates will have read the TCP/IP Volumes by Doyle and maybe even the RFC written by J Moy.

This book is also written by J Moy and it is basically the bible on OSPF. The great thing about this book is that is like a less dry version of the RFC and it explains the design decisions in OSPF.

Why did they choose to make it link state instead of distance vector? RIP had issues with large networks and the large updates being sent and your network diameter was limited due to the hop count limit. Why did they choose to run it over IP instead of making it a link layer protocol or run it over UDP or TCP? This is also explained in the book.

Creating a protocol takes a lot of work and making it interoperable is a challenge. Moy describes how they did interoperability tests where the first test was hosted at Proteon. It was a common occurence to see developers from several companies leaning over a competitor’s shoulder, trying to fix a bug!

I’m still reading the book but it has been great so far. I you get a Safari subscription you can read all the books you like. I recently did and I can really recommend it.

OSPF: Anatomy of a routing protocol
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5 thoughts on “OSPF: Anatomy of a routing protocol

  • June 25, 2012 at 3:54 am

    hey Daniel~have you read INE’s volumeII TS workbook?What do you think about those ten labs?After i have read a few labs,i think they are somehow too simple for the real lab.
    Any recommended material for the TS session ?
    last,your blog really helps me a lot

    • June 25, 2012 at 7:52 am

      So far no vendor has done a great job. The biggest reason is that the real TS topology is so much larger than any vendor is using. This will have effect psychologically. You can get a bit shocked by the size of it if it is the first time you go there. With that many devices you can of course test more things as well like more advanced BGP scenarios and such.

      Also the TS labs I’ve done so far sometimes seem a bit overly complicated and not in the kind of way that would really prepare you for the lab.

      The best I’ve seen so far is the Cisco360 mock labs which runs IOU and has a real size TS topology. It costs a bunch though.

      INE is on their way of updating their TS labs and it looks much better. It will be running on a similar size topology as Cisco on real devices.This will be the thing to go for when it is released.

      Good luck in your studies. Thanks for the compliments on the blog.

  • June 27, 2012 at 7:51 pm

    Oh man, I still have so many books to read and this is another interesting one!

  • June 29, 2012 at 4:10 pm

    I actually just got a used copy of this off Amazon. Great book. I especially loved his description of the meltdown caused by the circular sequence numbers in the first link state protocol they ran on the Arpanet. Make you realize how badly things can go wrong with thee protocols…

  • June 30, 2012 at 10:05 pm

    “R1–R2–R3(…when using MPLS, all the LSR’s will assign a local label for it (fine enough) but why does LDP share the upstream LSR assigned label with downstream LSR??? Is there any specific reason for doing it???”


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