Cisco Wireless Transmit Power Control
Power substation outside a VERY large data center in Atlanta,GA.
I’m going to start out by telling you something you probably already know. Every vendor has their own way of doing things. Sometimes it makes perfect sense, and other times you end up scratching your head wondering why that particular vendor implemented this feature or product. Since I have been spending a lot more time on wireless these days, I came across an issue that forced me to reconsider how transmit power control(TPC) actually works in a Cisco wireless deployment. I thought I would impart some of this information to you, dear reader, in the hopes that it may help you. If you spend a lot of time inside Cisco wireless LAN controllers, this may not be anything new to you.
The Need For TPC
If you have been around wireless long enough, you have probably dealt with wireless installs where all of the access points(AP) were functioning autonomously. While this isn’t a big deal in smaller environments, consider how much design work goes into a network with autonomous access points that number into the hundreds. It isn’t as simple as just deciding on channels and spinning all the access Continue reading
Updated Big Switch Labs
Just a quick note to say that Big Switch have updated their demo lab system. This is an entirely virtual lab environment that simulates a Big Switch network. You can try out both Big Cloud Fabric and Big Tap Monitoring Fabric.
The lab gives you full CLI & GUI access to a sandboxed environment, with controllers, leaf/spine switches, and endpoints. Big Switch have written a sample lab you can work through, to show off the features, but you’re not limited there. You’re free to try out whatever features you like.
If you’re interested in what they’re doing, I recommend signing up.
NB: Big Switch was a sponsor of NFD8. Usual disclaimer applies
Tech Talks: Load Sharing and Entropy Labels in MPLS Networks
Load sharing in MPLS networks is always an interesting topic, and we couldn’t possibly avoid it during our MPLS-focused Tech Talks – watch the video.
After discussing the load sharing intricacies we briefly dabbled with the concept of entropy labels.
Docker Networking 101 – Host mode
In our last post we covered what docker does with container networking in a default configuration. In this post, I’d like to start covering the remaining non-default network configuration modes. There are really 4 docker ‘provided’ network modes in which you can run containers…
Bridge mode – This is the default, we saw how this worked in the last post with the containers being attached to the docker0 bridge.
Host mode – The docker documentation claims that this mode does ‘not containerize the containers networking!’. That being said, what this really does is just put the container in the hosts network stack. That is, all of the network interfaces defined on the host will be accessible to the container. This one is sort of interesting and has some caveats but we’ll talk about those in greater detail below.
Mapped Container mode – This mode essentially maps a new container into an existing containers network stack. This means that while other resources (processes, filesystem, etc) will be kept separate, the network resources such as port mappings and IP addresses of the first container will be shared by the second container.
None – This one Continue reading
PQ Show 43 – HP Networking – Beyond Traditional Network Management
This is the last in a series of podcasts sponsored by HP, all recorded at HP’s Discover conference in Barcelona, Spain in early December 2014. The series is made up of interviews and technical discussions with HP engineers and lab geeks about products in HP’s networking portfolio. Ken Gott, Product Line Manager, joins Chris Young, Senior Solutions […]
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The post PQ Show 43 – HP Networking – Beyond Traditional Network Management appeared first on Packet Pushers Podcast and was written by Ethan Banks.
Don’t Underestimate Your Users
The “consumerisation of IT” has an interesting side-effect. Historically people mainly used computers for work. But now that many people have smartphones, tablets and laptops at home, their perception and understanding of technology has shifted. Old assumptions about training required when upgrading applications or client operating systems may no longer apply.
This comment at The Register aligns with what I’m seeing:
…We’re at the point now where users are using Windows 8 at home and wondering why the work computer is so dated. It’s the perception of IT people that users can’t handle change holding up that change, not the ability of the users. At home that same set of users has managed quite well with updated versions of Office, updated Windows, iPads, Android tablets, Facebook, video messaging and various other completely new things. Somehow they coped without extensive training and therapy. From what I’ve seen, it’s actually IT staff who don’t like Windows 8 and are trying to keep users away from it…
I can recall being involved in Office upgrades just a few years ago, and being nervous about how that would be perceived. We were concerned that there would be major push-back, because the exact locations of the buttons Continue reading
Network Automation @Interop Vegas 2015
In case you are planning on attending Interop in Las Vegas this year, I’d like to let you know about my two sessions, both centered around emerging methodologies and technologies in the networking space. Practical Network Automation With Ansible and Python This is going to be a 3 hour workshop, aiming to be a practical look into network automation. I picked the topics that I have been working with most heavily in this space, and I think this workshop will be a great way to get up to speed with some down-to-earth network automation methodologies.Network Automation @Interop Vegas 2015
In case you are planning on attending Interop in Las Vegas this year, I’d like to let you know about my two sessions, both centered around emerging methodologies and technologies in the networking space. Practical Network Automation With Ansible and Python This is going to be a 3 hour workshop, aiming to be a practical look into network automation. I picked the topics that I have been working with most heavily in this space, and I think this workshop will be a great way to get up to speed with some down-to-earth network automation methodologies.Flexible SSL & WordPress: Fixing “Mixed Content” Errors
As many are aware, CloudFlare launched Universal SSL several months ago. We saw lots of customers sign up and start using these new, free SSL certificates. For many customers that didn’t already have an SSL certificate, they were able to use “Flexible SSL”.
Flexible SSL creates a secure (HTTPS) connection between the website visitor and CloudFlare and then an in-secure (HTTP) connection between CloudFlare and the origin server. For any site using absolute links to assets (i.e. javascript, css, and image files), this can lead to a “Mixed Content” error.
Mixed Content = Mixed Protocol
What is “Mixed Content”? This can be understood as mixed protocol. When the webpage is loaded over SSL (HTTPS protocol), most browsers expect all of the assets to be loaded over the same protocol. Some browsers will display an error about loading “insecure content” while others will just block the insecure content outright.
This error only applies to pages loaded over SSL, since the browser is working to make sure that secure pages only load equally secure assets.
Wordpress Plugin Updates
The latest version of the CloudFlare plugin for Wordpress works to resolve a lot of these errors by altering the protocol within the Continue reading
Netvisor Takes SDN Switching Mainstream with $50M Series D
We closed our Series D in financing right before Christmas. This is a $50M round lead by Temasek and Ericsson. Temasek is a $170B plus sovereign fund out of Singapore that is best described as Berkshire Hathaway of Technology. They were the people responsible forinvestments into Alibaba. This is important to understand that with Netvisor achieving success in Enterprise Datacenter and Private Cloud markets, the bigger players now believe that SDN switching and applications on Server-Switches is pretty real.
The finding is primarily to scale our business side and help sell more products, build support infrastructure and create a application group that can write more applications on Netvisor to exploit the world of programmable networks.
Netvisor as an Application Platform
The best way to explain this is to draw a parallel between Netvisor as a switch Hypervisor and Smartphone.
When Apple released a IOS based smartphone, the world was full of small hardware devices like camera, GPS navigators etc. IOS (and later Android) become a software platform that allowed many applications to come of top of this platform.
Netvisor is creating the same paradigm for datacenter switching. Today, you have a physical fabric, a separate Observability fabric (using TAPS and Continue reading
OSPF inter-area and intra-area routing rules
The following lab focuses on intra-area and inter-area route selection process. For the sake of clarity, I put the final conclusions first, wrapped in a table form, with some explanations to ponder upon, followed by the different lab cases used to check OSPF route selection rules. For each case, I used interface costs and states […]
OSPF inter-area and intra-area routing rules
The following lab focuses on intra-area and inter-area route selection process. For the sake of clarity, I put the final conclusions first, wrapped in a table form, with some explanations to ponder upon, followed by the different lab cases used to check OSPF route selection rules. For each case, I used interface costs and states […]
OSPF routing protocol
OSPF Open shortest path first is a dynamic routing protocol which creates a topology between the routers to distribute routing information inside an Autonomous system. If you are not familiar with OSPF, don’t worry ! In this article OSPF will be explained in great detail. Are you interested in design aspect of OSPF, many OSPF design examples will […]
The post OSPF routing protocol appeared first on Network Design and Architecture.
Open Source Networking
We’ve heard a lot of Software Defined Networking (SDN), Open Networking, APIs, and policy models over the past few months (and years). There are days where it’s sickening to hear the term SDN, but even on those darkest days, the reality is that the network industry has a bright and open future. In this post, I’m going to share a list of networking projects that I’m aware of that are not only open, but also open source. It is definitely eye opening and extremely positive to see so much open source activity in the network industry.
From the movie Daylight starring Sly Stallone ++ Source: Flickfacts.com
OpenDaylight (ODL) – established in April 2013 is an open source Software Defined Networking (SDN) controller platform(s). There are different controller platforms for different use cases.
OpenFlow (OF) – established in the late 2000s, the OpenFlow 1.0 release launched in December 2009. The Open Networking Foundation took over the development (not actually coding) of OpenFlow when ONF formed in late March / early April in 2010.
Open vSwitch (OVS) – established in mid to late 2009 by the Nicira team to replace the standard Linux bridge. It’s Continue reading
OpenFlow (OF) – established in the late 2000s, the OpenFlow 1.0 release launched in December 2009. The Open Networking Foundation took over the development (not actually coding) of OpenFlow when ONF formed in late March / early April in 2010.
Open vSwitch (OVS) – established in mid to late 2009 by the Nicira team to replace the standard Linux bridge. It’s Continue reading
News Analysis: Cumulus Linux 2.5 Released + Validated Design Guides
One of my favorite companies to talk to and keep track of is Cumulus Networks, makers of Cumulus Linux, a network operating system that runs on whitebox switches. As I’m not in a build phase on the network I do most of my work on, I haven’t had a chance to try Cumulus Linux […]Lock-In Is Inevitable – Get Used to It!
For whatever reason (subliminal messages from vendor marketing departments?), I’m constantly brooding about the vendor lock-in, its inevitability, and the way supposedly disruptive companies try to use the fear of lock-in to persuade na├»ve customers to buy their products.
Read more ...BGP in 2014
The Border Gateway Protocol, or BGP, has been holding the Internet together, for more than two decades and nothing seems to be falling off the edge so far. As far as we can tell everyone can still see everyone else, assuming that they want to be seen, and the distributed routing system appears to be working smoothly. All appears to be working within reasonable parameters, and there is no imminent danger of some routing catastrophe, as far as we can tell. For a protocol designed some 25 years ago, when the Internet of that time contained some 10,000 constituent networks, its done well to scale fifty-fold, to carry in excess of half a million routed elements by the end of 2014.Open Source Networking
We’ve heard a lot of Software Defined Networking (SDN), Open Networking, APIs, and policy models over the past few months (and years). There are days where it’s sickening to hear the term SDN, but even on those darkest days, the reality is that the network industry has a bright and open future. In this post, I’m going to share a list of networking projects that I’m aware of that are not only open, but also open source. It is definitely eye opening and extremely positive to see so much open source activity in the network industry.
Edit/Note: updated list can be found here on GitHub. Feel free to issue a pull request to add or modify the list.
OpenDaylight (ODL) – established in April 2013 is an open source Software Defined Networking (SDN) controller platform(s). There are different controller platforms for different use cases.
OpenFlow (OF) – established in the late 2000s, the OpenFlow 1.0 release launched in December 2009. The Open Networking Foundation took over the development (not actually coding) of OpenFlow when ONF formed in late March / early April in 2010.
Open vSwitch (OVS) – established in mid to late 2009 by the Nicira team to Continue reading