Community Spotlight — PacketLife.net

Community SpotlightI’ve been reading articles by Jeremy Stretch for several years now. His site, PacketLife.net, may be best know for the useful cheat sheets that cover everything from IGP routing protocols to Wireshark Display filters. This site doesn’t end with cheat sheets. It also has many useful articles about all things networking. So if you’re looking for a site to add to you feedreader, check it out.

Links

Disclaimer–I continually get requests for a list of the blogs, podcasts and people I follow to “keep up” in this industry. As a result, I decided to start publishing some of the blogs I regularly read. Links to other content from PacketU or affiliated social channels should not be thought of as a universal endorsement or indication of independence or neutrality for a given external site. Readers should assess ALL applicable content before proceeding with actions that could adversely affect their environment.

Readers of this article may also enjoy:

  1. Community Spotlight — Daniel’s Networking Blog
  2. Blog Spotlight — Cisco Inferno
  3. Blog Spotlight — The Peering Introvert — Ethan Banks abstracts networking with words
  4. Blog Spotlight — Colin McNamara — OpenStack Nerd, CCIE, DevOps Junkie

The post Continue reading

Do You Believe in Magic?

We don't. But we DO believe in insanity, which seems to be running rampant these days in the networked world. After reading Gartner's new 2014 Magic Quadrant for the Wired and Wireless LAN Access Infrastructure, we are feeling a bit...

Response: Extreme Charges License Fee When Using OEM SFPs, Limits Bandwidth

Extreme Network now charges a license fee for ports that have 40G/100G OEM or third party SFPs installed. If you don't purchase a license within 90 days, it will limit bandwidth to 25%. How crappy is that ? Hiding the full price of the switch in SFP pricing strategies is a dumb idea that all the vendors have, what about simply being honest and calling it what it is - a per-port licensing fee designed to extract more revenue from a shrinking market.

The post Response: Extreme Charges License Fee When Using OEM SFPs, Limits Bandwidth appeared first on EtherealMind.

Coffee Break -Show 11

Health week on the Coffee Break - we are drinking water instead of coffee or kool-aid. Everything else remains the same.

Author information

Greg Ferro

Greg Ferro is a Network Engineer/Architect, mostly focussed on Data Centre, Security Infrastructure, and recently Virtualization. He has over 20 years in IT, in wide range of employers working as a freelance consultant including Finance, Service Providers and Online Companies. He is CCIE#6920 and has a few ideas about the world, but not enough to really count.

He is a host on the Packet Pushers Podcast, blogger at EtherealMind.com and on Twitter @etherealmind and Google Plus.

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The post Coffee Break -Show 11 appeared first on Packet Pushers Podcast and was written by Greg Ferro.

Simple Python Syslog Counter

Recently I did a Packet Pushers episode about log management. In it, I mentioned some of the custom Python scripts that I run to do basic syslog analysis, and someone asked about them in the comments.

The script I'm presenting here isn't one of the actual ones that I run in production, but it's close. The real one sends emails, does DNS lookups, keeps a "rare messages" database using sqlite3, and a few other things, but I wanted to keep this simple.

One of the problems I see with getting started with log analysis is that people tend to approach it like a typical vendor RFP project: list some requirements, survey the market, evaluate and buy a product to fit your requirements. Sounds good, right? The problem with log analysis is that often you don't know what your requirements really are until you start looking at data.

A simple message counting script like this lets you look at your data, and provides a simple platform on which you can start to iterate to find your specific needs. It also lets us look at some cool Python features.

I don't recommend pushing this too far: once you have a decent idea Continue reading

Simple Python Syslog Counter

Recently I did a Packet Pushers episode about log management. In it, I mentioned some of the custom Python scripts that I run to do basic syslog analysis, and someone asked about them in the comments.

The script I'm presenting here isn't one of the actual ones that I run in production, but it's close. The real one sends emails, does DNS lookups, keeps a "rare messages" database using sqlite3, and a few other things, but I wanted to keep this simple.

One of the problems I see with getting started with log analysis is that people tend to approach it like a typical vendor RFP project: list some requirements, survey the market, evaluate and buy a product to fit your requirements. Sounds good, right? The problem with log analysis is that often you don't know what your requirements really are until you start looking at data.

A simple message counting script like this lets you look at your data, and provides a simple platform on which you can start to iterate to find your specific needs. It also lets us look at some cool Python features.

I don't recommend pushing this too far: once you have a decent idea Continue reading

Article Archives

Here are some of the most popular posts on Revolution Wi-Fi, grouped by topic.

Note - This is NOT a comprehensive archive of articles on this blog.

802.11ac Gigabit Wi-Fi Series:
High-Density Wi-Fi Design Series:
Wi-Fi Quality of Service Series:
  1. Part 1 - Background Information
  2. Part 2 - IEEE 802.11e Principles
  3. Part 3 - User Priorities, Access Categories and Queues
  4. Part 4 - Arbitration Interframe Spacing
  5. Part 5 - Contention Window and Final Thoughts
Wi-Fi Roaming Analysis Series:
  1. Part 1 - Connection Control and Importance of Roaming Analysis
  2. Part 2 - The Many Variations of Wi-Fi Roaming
  3. Part 3 Continue reading

Hot Potatoes and Network Neutrality

Hot Potatoes and Network Neutrality

by Cengiz Alaettinoglu, CTO - July 1, 2014

If you are reading this blog, you probably know what I mean by hot potatoes. The routing in the Internet is often referred to as hot potato routing. This analogy comes from how BGP and IGP work together so that incoming IP packets to an Autonomous System (AS) are treated like hot potatoes. If someone hands you a hot potato, what do you do? You pass it to the next person as soon as possible. This is what BGP and IGP routing do. When IP packets enter a network, they are delivered to the next AS as soon as possible. 

Since most of the network neutrality debate is regarding Netflix, Comcast and Verizon these days, let’s see how hot potato routing works in this scenario. Netflix buys transit services from Cogent, another service provider (see our related white paper on peering relationships). Their agreement is that Cogent will deliver Netflix’s IP packets to their destinations. I, as a consumer, buy “Internet service” from Time Warner. My agreement with them is for all-I-can-eat Internet access with up to 30Mbps download speeds for about $80 a month. Continue reading

Dock Dock.  Who’s there?

In my previous post about Docker, I focused on an introduction to networking with Docker.  That post had a fair amount of traction mainly due to it being #dockercon the week it was published, and seemingly, people had an interest in learning more about it.  Following the post, there were a few folks (@hartley and others) that pointed me to some great links about more advanced concepts in Docker and a site that validated what I was speculating with leveraging overlay tunnels as means for connectivity between nodes running Docker.
Picture
After reading through a few posts and the links about libswarm and libchan, it was on my mental to-do list to learn more about them and test more advanced designs.  In the meantime, the friendly folks at Digital Ocean let me know about a local meetup where James Turnbull, VP of Services at Docker, was presenting.  The meetup was tonight.  It was a short presentation, but for me, it was eye opening (it may be because I’ve been *mostly* focused on networking).  So, you won’t find a deep dive here like the last post, but rather, some general thoughts on Docker motivated from Continue reading

The Impact of White Box on Cloud Networking

The adoption of cloud networking architectures by both the hyper-scale cloud companies and increasingly enterprise networks proves the need for open standards and modern networking software to gain the benefits of agility, programmability and resiliency. These architectures are all driven by the move to standardized topologies and container-scale deployment to achieve cloud economics.

The recent Facebook introduction of a reference design to align to the OCP (Open Compute Platform) server project with a network switch (“Wedge”) based on a Linux OS is a good benchmark for the use of open standards, control and merchant silicon. While many may view this as a threat to legacy proprietary networking, to me it’s a welcome validation of Arista’s approach to building modern software that is open and programmable as opposed to a proprietary, bloated and complex legacy OS. It is also a symbol of Arista’s co-development of APIs offering access for specific application control in Facebook’s network. This is a fitting example of how “white box” technology could be applied to a specific SDN use case. It is not trying to address broad data center use with multiple applications and mobile workloads.

Arista EOS for Universal Workloads and Workflows

Two factors are driving Continue reading

Internets of Interest for 30th June 2014

  Collection of useful, relevant or just fun places on the Internets for 30th June 2014 and a bit commentary about what I’ve found interesting about them: Minimum Viable Bureaucracy, June 2014 Edition // Speaker Deck – Enjoyed this presentation on “Minimum Viable Bureauracy” – some stimulating ideas on how to build better managers of […]

The post Internets of Interest for 30th June 2014 appeared first on EtherealMind.

Spine/Leaf Topology Explorer with Ansible

I’ve mentioned before the need for networks to be addressed in a very programmatic way. Very often, I’ve found the discussion is actually a lot less about “programming language” details and more about getting rid of the methodology of addressing the network as a mere “collection of boxes” (see “Box Mentality“).

Instead, we have the ability to address the network as any developer would address the distributed components of an application. We acknowledge that networks are a distributed system – it’s what makes them as scalable as they have been. However, it’s important to understand we can address configuration and troubleshooting needs in a unified, automated way as well.

My goal in this post is to explore one particular application of such a methodology. I will use Ansible to first create a dataset that represents a spine/leaf network topology – also demonstrating how it might scale beyond my small lab implementation – then I will move into some kind of network task based on this information.

I have access to a few Cisco Nexus 9000 switches in the lab, and I wanted to be able to model a spine/leaf topology in a very elegant way that would (theoretically) scale as Continue reading

Show 194 – SDN Northbound Interfaces with Sarwar Raza + Colin Dixon

At a conference I attended in late 2013 or early 2014 (I’ve forgetten which one), I was privileged to hear Sarwar Raza (HP, ONF) discuss the challenge of creating and implementing SDN northbound interfaces (NBI). Then at the Open Daylight Summit in February 2014, I found myself in a conversation with Colin Dixon (Brocade, formerly […]

Author information

Ethan Banks

Co-host at Packet Pushers

Ethan Banks, CCIE #20655, has been managing networks for higher ed, government, financials and high tech since 1995. Ethan co-hosts the Packet Pushers Podcast, which has seen over 2M downloads and reaches over 10K listeners. With whatever time is left, Ethan writes for fun & profit, studies for certifications, and enjoys science fiction. @ecbanks
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The post Show 194 – SDN Northbound Interfaces with Sarwar Raza + Colin Dixon appeared first on Packet Pushers Podcast and was written by Ethan Banks.

Spine/Leaf Topology Explorer with Ansible

I’ve mentioned before the need for networks to be addressed in a very programmatic way. Very often, I’ve found the discussion is actually a lot less about “programming language” details and more about getting rid of the methodology of addressing the network as a mere “collection of boxes” (see “Box Mentality”). Instead, we have the ability to address the network as any developer would address the distributed components of an application.

Spine/Leaf Topology Explorer with Ansible

I’ve mentioned before the need for networks to be addressed in a very programmatic way. Very often, I’ve found the discussion is actually a lot less about “programming language” details and more about getting rid of the methodology of addressing the network as a mere “collection of boxes” (see “Box Mentality”). Instead, we have the ability to address the network as any developer would address the distributed components of an application.

DNS Packet

The Naked DNS Packet







The above shows the DNS Opcodes in a DNS request.








Additional insight into the packet - As you can see that the DNS server responding was not authoritative and supported recursion.
1 … 3,640 3,641 3,642 3,643 3,644 … 3,752