Dave Oran joins Donald and I to talk about the history of DECnet at Digital Equipment—including the venerable IS-IS interior gateway protocol. Outro Music: Danger Storm Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 3.0 License http://creativecommons.org/licenses/by/3.0/
Multi-Instance IS-IS One of the nice things about IS-IS is the ability to run IPv6 and IPv4 in the same protocol, over a single instance. So long as the two topologies are congruent, deploying v6 as dual stack is very simply. But what if your topologies are not congruent? The figure below illustrates the difference.…
I sat with Greg Ferro over at Packet Pushers for a few minutes at the Prague IETF. We talked about Openfabric and how we are overusing BGP in many ways, as well as other odds and ends.
This is the blog post by Ivan I discuss in the video, and this is an older post here on Rule11 about the same topic, if you prefer your explanations written.
A couple of weeks ago, I attended a special segment routing Networking Field Day. This set me to thinking about how I would actually use segment routing in a live data center. As always, I’m not so concerned about the configuration aspects, but rather with what bits and pieces I would (or could) put together…
OSPF and IS-IS, both link state protocols, use mechanisms that manage flooding on a broadcast link, as well as simplify the shortest path tree passing through the broadcast link. OSPF elects a Designated Router (or DR) to simplify broadcast links, and IS-IS elects a Designated Intermediate System (or DIS—a topic covered in depth in the…
At a fundamental level, OSPF and IS-IS are similar in operation. They both build neighbor adjacencies. They both use Dijkstra’s shortest path first (SPF) to find the shortest path to every destination in the network. They both advertise the state of each link connected to a network device. There are some differences, of course, such…