Late last week, Cyrus Durgin from Luminus Networks published an article on SDx Central titled “The (R)evolution of Network Operations.” You may notice that my name is mentioned at the bottom of the article as someone who provided feedback. In this post, I’d like to share some thoughts—high-level and conceptual in nature—on network operations and Luminus Networks.
I was first introduced to Luminus Networks when I met its CEO, Kelly Wanser, at the Open Networking User Group (ONUG) meeting in New York City last November. We met again in the Denver area in late December, and Kelly gave me a preview of what Luminus was building. I must confess that I was immediately intrigued by what Kelly was describing. One key thing really jumped out at me: we need to treat the network as a system, not as a bunch of individual elements.
When it comes to network monitoring/management/operations, so many of the tools are focused on the individual elements that comprise a network: provisioning a switch, pushing configuration changes to a router or group of routers, polling counters from interfaces on switches, etc. While there’s nothing wrong with any of these things, it seems to me that there’s Continue reading
Some people change their SSH port on their servers so that it is slightly harder to find for bots or other nasties and while that is generally viewed as an action of [security through obscurity](https://en.wikipedia.org/wiki/S
Docker takes a slightly different approach with its network drivers, confusing new users which are familiar with general terms used by other virtualization products. If you are looking for a way to bridge the container into a physical network, you have come to the right place. You can connect the container into a physical Layer 2 network by using macvlan driver. If you are looking for a different network connection, refer to my docker network drivers post.
Before I begin, you should check some basics on what macvlan is, why it is a better alternative to a linux bridge and how it compares with ipvlan.
Important: As of Docker 1.11 macvlan network driver is part of Docker’s experimental build and is not available in the production release. You can find more info on how to use the experimental build here. If you are looking for a production ready solution to connected your container into a physical Layer 2 network, you should stick to pipework for the time being.
Last but not least, macvlan driver requires Linux Kernel 3.9 or greater. You can check your kernel version with uname -r. If you’re running RHEL (CentoOS, Continue reading
cd sflow-rtThe dashboard web interface shown in the screen shot should now be accessible. Run a test to see data in the dashboard. The following test created the results shown:
./get-app.sh sflow-rt mininet-dashboard
./start.sh
sudo mn --custom extras/sflow.py --link tc,bw=10 --topo tree,depth=2,fanout=2 --test iperfThe dashboard has three time series charts that update every second and show five minutes worth of data. From top to bottom, the charts are:
One of my students asked me this question a month ago. “What is the difference between PIM Sparse Mode and PIM SSM (Source Specific Multicast)?” But, since I had two CCDE bootcamps in one month, I didn’t have time to answer the question on this platform. By the way I have seen this mis understanding […]
The post PIM Sparse Mode Vs PIM SSM appeared first on Cisco Network Design and Architecture | CCDE Bootcamp | orhanergun.net.
On May the 17th I passed the CCDE practical in Madrid and became Swedens 2nd CCDE, CCDE #20160011. This post describes my journey to passing the CCDE practical in my 1st attempt and the materials that I used to do so.
Let me start by saying that this is a tough exam, a very tough exam. You need to be an expert in RS and SP technologies and there is no instant feedback in the exam, like you would get in the CCIE lab. In the CCIE lab you will see you are missing routes or if your output does not match the output the lab guidelines told you to match. In the CCDE practical there will be very few questions that you are 100% sure that you got the optimal answer. Design is a more subjective skill than implementation. I had several moments where I felt that I could just as well leave because there was no chance I was going to pass the lab. You need to be mentally strong to put those thoughts aside and just keep performing your best throughout the whole exam. You might be doing a lot better than you think.
The first section Continue reading