Is SDN API directionality absurd?
I was finally catching up on a number of posts I'd saved to read later and noticed the prevalent use of "Northbound" and "Southbound". I'm now starting to question whether these terms are necessary or accurate.
Is SDN API directionality absurd?
I was finally catching up on a number of posts I'd saved to read later and noticed the prevalent use of "Northbound" and "Southbound". I'm now starting to question whether these terms are necessary or accurate.
Dictionary definition
Let's start with the Oxford English Dictionary definition of these terms.
northbound | ˈnɔːθbaʊnd | adjective travelling or leading towards the north: northbound traffic.
southbound | ˈsaʊθbaʊnd | adjective travelling or leading towards the south: southbound traffic | the southbound carriageway of the A1.
As our interfaces are static and can't travel one can assume the intent of these adjectives in our context is to indicate that the interfaces are leading in the specified direction.
On Directionality as a descriptor
Categorizing an API by directionality is rather perplexing IMHO.
Specify directionality without a reference point is misleading For example, OVSDB is a northbound API for Open vSwitch but southbound API for an SDN controller.
For SDN controllers, there are two types of interfaces:
User-Facing or Application-Facing (formerly Northbound)
This API is designed to expose higher-order functions in such a way that they can easily be consumed by humans and programmers.
By this logic, we can include any "
Community Show – CCNA Data Center Part1 with Anthony Sequeira and Orhan Ergun
[player] In this first part of CCNA Datacenter sessions , Anthony Sequeira and Orhan Ergun are talking about the topics in the blueprint. They identify all the technologies which you should know for the CCNA Datacenter exam. Topics include : DCICN exam which is the first exam. DCICT exam which is the second exam. Datacenter […]
The post Community Show – CCNA Data Center Part1 with Anthony Sequeira and Orhan Ergun appeared first on Packet Pushers.
Community Show – CCNA Data Center Part1 with Anthony Sequeira and Orhan Ergun
In this first part of CCNA Datacenter sessions , Anthony Sequeira and Orhan Ergun are talking about the topics in the blueprint. They identify all the technologies which you should know for the CCNA Datacenter exam. Topics include : DCICN exam which is the first exam. DCICT exam which is the second exam. Datacenter Fundamentals, […]
Author information
The post Community Show – CCNA Data Center Part1 with Anthony Sequeira and Orhan Ergun appeared first on Packet Pushers Podcast and was written by Orhan Ergun.
Interview: Reduce Costs and Gain Efficiencies with SDDC
A few days ago I had an interesting interview with Christoph Jaggi discussing the challenges, changes in mindsets and processes, and other “minor details” one must undertake to gain something from the SDDC concepts. The German version of the interview is published on Inside-IT.ch; you’ll find the English version below.
Read more ...Is SDN API directionality absurd?
I was finally catching up on a number of posts I'd saved to read later and noticed the prevalent use of "Northbound" and "Southbound". I'm now starting to question whether these terms are necessary or accurate.
Why I gave up Networking for Software
It's now been 3 months since I transitioned from Networking to Software. This is a retrospective piece on my reasons for giving up on Networking.
A Quick Look at MPLS-TE
Introduction
I’m currently designing and implementing a large network which will run MPLS.
This network will replace an old network that was mainly L2 based and did not
run MPLS, only VRF lite. There are a few customers that need to have diverse
paths in the network and quick convergence when a failure occurs.
This led me to consider MPLS-TE for those customers and to have plain MPLS
through LDP for other customers buying VPNs. What is the usage for MPLS-TE?
Weaknesses of IGP
When using normal IP forwarding a least cost path is calculated through an IGP,
such as OSPF or ISIS. The problem though is that only the least cost path will
be utilized, any links not on the best path will sit idle, which is a waste of
bandwidth. IGP metrics can be manipulated but that only moves the problem to
other links, it does not solve the root cause. Manipulating metrics is cumbersome
and prone to error. It’s difficult to think of all the traffic flows in the network
and get all the metrics correct. IGPs also lack the granularity in metrics to
utilize all the bandwidth in the network.
RSVP-TE
RSVP in the past was Continue reading
Finally: a Virtual Switch Supports BPDU Guard
Nexus 1000V release 5.2(1)SV3(1.1) was published on August 22nd (I’m positive that has nothing to do with VMworld starting tomorrow) and I found this gem in the release notes:
Enabling BPDU guard causes the Cisco Nexus 1000V to detect these spurious BPDUs and shut down the virtual machine adapters (the origination BPDUs), thereby avoiding loops.
It took them almost three years, but we finally have BPDU guard on a layer-2 virtual switch (why does it matter). Nice!
Response – Do We Need To Redefine Open?
Tom Hollingsworth wrote a great post on whether or not we need to redefine "Open". My response was too long for a comment, so here it is!
Response – Do We Need To Redefine Open?
Tom Hollingsworth wrote a great post on whether or not we need to redefine "Open". My response was too long for a comment, so here it is!
Open Source vs Free Software
The first item is just a point of clarification. While the terms "Open Source" and "Free Software" are often used interchangeably there is a difference.
The two terms describe almost the same category of software, but they stand for views based on fundamentally different values. Open source is a development methodology; free software is a social movement. - Richard Stallman
You can read the full article here but the TL;DR version is that while a high percentage of Open Source software is Free Software, the definition of Open Source is less strict about guaranteeing freedoms.
...with that out of the way, let's move to "open"
On "open" and "openness"
I like the Wikipedia description of "openness":
Openness is an overarching concept or philosophy that is characterized by an emphasis on transparency and free unrestricted access to knowledge and information as well as collaborative or cooperative management and decision making rather than a central authority. - Wikipedia
It highlights some key terms which our "open" things should be adhering Continue reading
Response – Do We Need To Redefine Open?
Tom Hollingsworth wrote a great post on whether or not we need to redefine "Open". My response was too long for a comment, so here it is!
Fun with Fig (and Docker)
I first heard of Fig when I read about Docker acquiring Orchard, a container hosting service, back in July. Last week I finally got to read a little more about it and it just so happens it is the missing piece of the puzzle in a couple of projects that I am working on right now!
Fun with Fig (and Docker)
I first heard of Fig when I read about Docker acquiring Orchard, a container hosting service, back in July. Last week I finally got to read a little more about it and it just so happens it is the missing piece of the puzzle in a couple of projects that I am working on right now!
Fun with Fig (and Docker)
I first heard of Fig when I read about Docker acquiring Orchard, a container hosting service, back in July. Last week I finally got to read a little more about it and it just so happens it is the missing piece of the puzzle in a couple of projects that I am working on right now!
What does Fig do?
The best way I would describe Fig is like Vagrant for Docker containers. If you don't know what Vagrant is, or aren't using it then you are missing out!
Fig lets you bring up and tear down docker containers (single or multiple) with a simple command.
To do this, you express the desired configuration in a YAML file, fig.yml.
Getting started
On OSX, you'll need to have an accessible Docker environment. The easiest way to do this is with Homebrew and boot2docker
brew install docker
brew install boot2docker
boot2docker init
boot2docker start
export DOCKER_HOST=tcp://$(boot2docker ip 2>/dev/null):2375
# Install Fig
pip install fig
If you don't have Python and/or pip installed you may want to install the fig binary
Writing a Fig file for Open vSwitch
Let's say you are doing some integration Continue reading
Replacing Traditional TV & DVR with Little Streaming Boxes
After nine years with Dish Network, I’ve replaced it with an AppleTV and Roku 3 ($99 each, last time I looked). Having done that, what’s life like without traditional TV & DVR? In a nutshell, it’s just fine. My kids watch a lot of YouTube, and did before I retired Dish. I was bored […]Flowcontrol, port buffers and dropped packets
A few days ago a customer called worried by the flowcontrol counters increasing on his Cisco 4510 switch, he just sent me this asking for an explanation: CORE_4510#show interfaces flowcontrol Port Send FlowControl Receive FlowControl RxPause TxPause admin oper admin …Vocus Acquisition of FX: Good for Customers?
Consolidation is happening in the New Zealand wholesale ISP market, with Vocus acquiring FX. Consolidation can lead to less competition, or it can strengthen it, by making players stronger and more viable. This acquisition should strengthen the market, and hopefully open up new service offerings.
In July Vocus Communications announced its intention to acquire FX Networks. From the press release:
FX owns a unique and high quality fibre optic network consisting of 4,132 kms of modern ducted fibre cable covering both the North and South Islands of New Zealand. The company has 365 customers including 43 of the Top 100 companies in New Zealand.
Vocus will acquire FX for an enterprise value of NZ$115.8m (~A$107.7m). The FX business is expected to deliver NZ$13.5-$14.5m of EBITDA in the first 12 months post acquisition (excluding transaction and integration expenses).
The combination of Vocus and FX strengthens both businesses. Vocus will emerge as the third largest network operator in NZ and the clear leader in trans-Tasman telecommunications and data centres.
Vocus has their own fibre network around Australia, and has a significant international network, with high-level peering. In 2012 they purchased Maxnet, a New Zealand ISP and Data Center Continue reading
ipSpace.net Is on CloudFlare (and IPv6)
After a week of testing, I decided to move the main ipSpace.net web site (www.ipspace.net) as well as some of the resource servicing hostnames to CloudFlare CDN. Everything should work fine, but if you experience any problems with my web site, please let me know ASAP.
2014-08-27: Had to turn off CloudFlare (and thus IPv6). They don't seem to support HTTP range requests, which makes video startup time unacceptable. Will have to move all video URLs (where the HTTP range requests are expected coming from streaming clients) to a different host name, which will take time.
Collateral benefit: ipSpace.net is now fully accessible over IPv6 – register for the Enterprise IPv6 101 webinar if you think that doesn’t matter ;)
Useful Links — Cisco Quicklinks
I just wanted to take a quick moment to share a site Dan DeBusschere has created. This site is a list of very useful config snippets, information and links. Most of the content is focused on Datacenter and UCS. If you support this type of environment, check it out.
Disclaimer: This article includes the independent thoughts, opinions, commentary or technical detail of Paul Stewart. This may or may not reflect the position of past, present or future employers.
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