Archive

Category Archives for "ipSpace.net"

RFC 8196: IS-IS Autoconfiguration

Finally a group of engineers figured out it’s a good idea to make things less complex instead of heaping layers of complexity on top of already-complex kludges.

RFC 8196 specifies default values and extensions to IS-IS that make it a true plug-and-play routing protocol. I wonder when we’ll see it implemented now that everyone is obsessed with intent-based hype.

IPv6 Link-Local Addresses and VLAN Interfaces

One of my readers sent me an email that’s easiest paraphrased into: “Why can’t I have a different IPv6 link-local address (LLA) on every access port connected to a VLAN interface?

There’s probably nothing stopping someone from implementing such an approach, but it would go against the usual understanding of how bridging and routing interact in L2+L3 switches.

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Automation or Orchestration?

Have you ever wondered what the difference between automation and orchestration is?

Wikipedia defines automation as use of various control systems for operating equipment. The definition I prefer (because it’s easier to understand in network automation environment) is elimination of well-defined repeatable manual tasks – the emphasis being on well-defined and repeatable.

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Swimlanes, Read-Write Transactions and Session State

Another question from someone watching my Designing Active-Active and Disaster Recovery Data Centers webinar (you know, the one where I tell people how to avoid the world-spanning-layer-2 madness):

In the video about parallel application stacks (swimlanes) you mentioned that one of the options for using the R/W database in Datacenter A if the user traffic landed in Datacenter B in which the replica of the database is read-only was to redirect the user browser with the purpose that the follow up HTTP POST land in Datacenter A.

Here’s the diagram he’s referring to:

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Sample Network Automation Ansible Playbooks

I developed over a dozen different Ansible-based network automation solutions in the last two years for my network automation workshops and online course, and always published them on GitHub… but never built an index, or explained what they do, and why I decided to do things that way.

With the new my.ipSpace.net functionality I added for online courses I got the hooks I needed to make the first part happen:

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Asymmetrical Traffic Flows and Complexity

One of my readers sent me a list of questions on asymmetrical traffic flows in IP networks, particularly in heavily meshed environments (where it’s really hard to ensure both directions use the same path) and in combination with stateful devices (firewalls in particular) in the forwarding path.

Unfortunately, there’s no silver bullet (and the more I think about this problem, the more I feel it’s not worth solving).

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Moving to Summer Schedule

The inevitable summer decline of visitors has started, so I'm switching (like every summer) to a lower publishing frequency. Given my current focus (here and here) expect one network automation post and one other in-depth post every week… and maybe an occasional this-is-worth-reading link.


Working in the summer office ;)

Take some time off, enjoy the vacations, and I hope to meet you in the September online course ;)

Monitoring SDN Networks: Featured Webinar in June 2016

Monitoring SDN Networks is the featured webinar of June 2017, and in the featured video Terry Slattery (CCIE#1026) talks about network analysis of SDN.

If you’re a trial subscriber, log into my.ipspace.net, select the webinar from the first page, and watch the video marked with star… and if you’d like to try the ipSpace.net subscription register here.

Trial subscribers can also use this month's featured webinar discount to get a 25% discount (and get closer to the full subscription).

First Speakers in Autumn Network Automation Course

Today I can tell you who the first speakers in the autumn 2017 network automation online course will be.

Sounds promising? Why don’t you register before we run out of early-bird tickets?

Packet Fabric on Software Gone Wild

Imagine a service provider that allows you to provision 100GE point-to-point circuit between any two of their POPs through a web site and delivers in seconds (assuming you’ve already solved the physical connectivity problem). That’s the whole idea of SDN, right? Only not so many providers got there yet.

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