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!
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!
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!
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
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!
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.
The post Useful Links — Cisco Quicklinks appeared first on PacketU.
What is an Automatic Transfer Switch (Power)?
In response to the power redundancy article I wrote yesterday, a few comments came in. One of them (thanks, Mike!) mentioned an automatic transfer switch (ATS), a useful tool in a redundant power strategy. What is an ATS? There are many types of electrical transfer switches whose primary purpose is to divert the […]Missing Synergies & HP’s SDN
As someone who’s been monitoring HP’s SDN strategy for years now, news that Bethany Mayer is headed to Ixia is rather interesting. Despite HP’s networking division having had some successes and gaining small bits of market share here and there, the fact they they are leaders in the SDN space seems to go unnoticed by the […]Cloud Orchestration System Is an Ideal Controller Use Case
A while ago I explained why OpenFlow might be a wrong tool for some jobs, and why centralized control plane might not make sense, and quickly got misquoted as saying “controllers don’t scale”. Nothing could be further from the truth, properly architected controller-based architectures can reach enormous scale – Amazon VPC is the best possible example.
Read more ...Leveraging Cisco NX-API with Ansible to Make Your Life Easier
I had a conversation recently with someone who has more of a sysadmin background. We started talking about the intersection of DevOps and networking and while his environment wasn’t large, there was one pain point he talked about – he doesn't have access to the network switches to ensure they are configured properly for “his” servers and to ensure packets aren't being dropped, etc. when there are issues with the application, server, or network. And by the way, he really doesn't want access to the data center switches, because after all, many fear logging into network devices that are in production.
Could DevOps and network automation help here?
Could DevOps and network automation help here?
In fact, the answer is yes. The goal is to get the right data into the right hands as quick as possible. An automation platform can be used to query the switch to get the exact data the admin needs. For those that have help desks supporting large campus networks, the same philosophy can be used there as well. Help desk, junior admins, and cross-functional team members can now get what they need in just a few seconds.
In order to test this out, I’ve Continue reading
In order to test this out, I’ve Continue reading
FabricPath Multidestination Trees
FabricPath has many advantages over the classical Spanning Tree Protocol. Mainly because it can use ECMP (Equal Cost Multi Paths) Routing. For unicast frames it uses the well known Switch-ID that is inserted in a FabricPath header. This will be explained in a future post for sure. I have been intrigued regarding how multicast […]Street Power vs. UPS Power In Redundant Power Supply Devices
A question came into the Packet Pushers mailbox along these lines. If a unit has two power inputs, should one go to UPS and one to street power, or is it better to have both power supplies fed by the same UPS? The issue with raw street power is that it isn’t conditioned. […]Load Balancing Lab setup
Virtual Loadblanacers
Nowadays, you don't need a physical load balancer to setup a lab. Almost each and every vendor offers a "virtual appliance", which is just their appliance repacked as a virtual machine:Here is a list of few such virtual loadbalancers:
There are even opensource alternatives such as:
- OpenBSD's relayd - in OpenBSD very few tutorials are needed as the man pages are complete, but here are some few links: tutorial1 tutorial2. It has full support for many advance loadbalncer's features.
I plan to try it out. - nginx
- Linux LVS
So building a virtual lab on a laptop is just one download away, isn't it?
No, there are to missing pieces: Network topology with a router and web servers with content which is suitable for such labs.
Luckily for you, I have just setup such a lab, and I welcome you to use it as well.
Network topology
Basic topology
The usual loadbalancer lab looks like this:
But this is not how loadbalncers are usually deployed. And its also not the best way to deploy them, as not all traffic needs to go through the loadbalancer.
Realistic topology
.png) |
| Topology Continue reading |
Quick Take: Wider Channel Widths Are Flashy but Not Efficient
I've been thinking of writing a well-articulated blog post on why the preference for high-density Wi-Fi networks is smaller channel width over larger channel width. This post is NOT that.Instead, I was on Twitter articulating some of the logical points why smaller channel widths provide better aggregate capacity than larger channel widths (assuming you deploy enough radios and take advantage of all the spectrum at your disposal). Here is a quick recap of those points.
You might want to reference my SNR to MCS Index Mapping Table, which shows why larger channels result in a reduction in modulation rate that can often offset the gain from using the wider bandwidth in the first place. And my 802.11ac Receiver Sensitivity charts show that you have to have a really great signal strength for wider channels to even be considered, but watch out in your design because overcompensating to achieve higher signal strength will increase co-channel interference (CCI) which travels a LONG ways! Finally, my post on 802.11ac Adjacent Channel Interference (ACI) shows that wider channels create more ACI than smaller channels, and ACI is even more detrimental and unfriendly than CCI. Therefore, radio receivers require greater adjacent channel Continue reading