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Category Archives for "Networking"

SDN, data center predictions for 2015

The predictions for data center and SDN in 2015 are still rolling in. Technology Business Research says software will pervade the data center while start-up Plexxi believes policy and disaggregation will be front and center.Here’s the link to TBR’s 2015 Data Center Predictions. Some of the more interesting prognostications in it are the acceleration of SDN in the enterprise and the ability of hyperconvergence to converge.To read this article in full or to leave a comment, please click here

Why SDN all-stars are heading to Brocade

Why is it that a who’s who of SDN developers is landing at Brocade? Over the past two years, the company has lured a handful of industry All-Stars to work on software enabling its networking portfolio, including Fibre Channel storage-area network switches, and Ethernet switches and routers. The most recent hire is Michael Bushong, who jumped from start-up Plexxi to Brocade late last year to run product management.To read this article in full or to leave a comment, please click here

How Does MPLS-TE Interact with QoS

MPLS Traffic Engineer is sometimes promoted as a QoS solution (it seems bandwidth calendaring is a permanent obsession of some networking engineers, and OpenFlow is no more a solution than MPLS-TE was ;), but in reality it’s pretty hard to make the two work together seamlessly (just ask anyone who had to implement auto-bandwidth MPLS-TE in a large network).

Not surprisingly, we addressed the topic during our MPLS Tech Talk.

HTIRW: IETF Organizational Structure

So far, we’ve looked at the naming system, routing, and policy in our travel through “internet land.” Last time, we took a quick look at some of the various organizations that create the standards that make the internet work. This time I’m going to start looking in more depth at one specific standard body, or […]

Author information

Russ White

Principal Engineer at Ericsson

Russ White is a Network Architect who's scribbled a basket of books, penned a plethora of patents, written a raft of RFCs, taught a trencher of classes, and done a lot of other stuff you either already know about — or don't really care about. You can find Russ at 'net Work, the Internet Protocol Journal, and his author page on Amazon.

The post HTIRW: IETF Organizational Structure appeared first on Packet Pushers Podcast and was written by Russ White.

Parsing Junos XML with Python

I’ll admit it – I’ve drunk the “Network Engineers should learn programming” Kool-Aid. In so doing, I’m gearing up for Kirk Byers upcoming “Python for Network Engineers” course by hacking a bit of Python most every evening. Kirk has recently released a Python “wrapper” module for the popular Python SSH module “Paramiko” that simplifies connections […]

Author information

Will Dennis

Will Dennis

Will Dennis has been a systems and network administrator since 1989, and is currently the Network Administrator for NEC Laboratories America, located in Princeton NJ. He enjoys the constant learning it takes to keep up with the field of network and systems administration, and is currently pursuing the Cisco CCNP-R/S certification. He can be found on the Twitters as @willarddennis, and on Google Plus.

The post Parsing Junos XML with Python appeared first on Packet Pushers Podcast and was written by Will Dennis.

My 2015 goals

I’ve always sort of set goals for myself, but I never really write any of them down.  This year, after talking to a friend about it, I decided to write down some actual goals for 2015.  What really struck me about the conversation was a single sentence he said.  I believe the exact words he used were “Write them down and you’ll be amazed at how motivated you can be”.  Since it certainly sounded like he was speaking from experience, here’s my list.  Some are more subjective which will make them harder to ‘check off’ than others.  Some are related to my work/career, some are personal, and some are just sort of for fun. 

Run a marathon – Some of you know I made a serious attempt at this 2 years ago.  It started with others offering tips and training schedules, continued with me disregarding the training plan, and ended with me doing it wrong and messing up my knee.  So this year, I’m going to make a serious attempt at following a training schedule and try and get this done.  I’ll aim for the Twin Cities marathon which happens Continue reading

Remove Duplicates from Pocket List

One problem I’ve noticed with my Pocket list is that my reading list contains quite a few duplicate entires. Sometimes I forget I saved an article and I save it multiple times, or maybe I save it across-sources (like Twitter or Facebook, or just browsing.

It looks like Pocket has some protective capabilities around this. If I endlessly spam the button provided to me by my Pocket chromecast extension, Pocket only saves the one copy and all is good.

However, take the following example. Many of the articles we read and put into our Pocket list use some kind of URL options for tracking purposes:

?utm_source=social&utm_medium=twitter&utm_campaign=1215

If you arrive to an article from different sources, but save both to Pocket, Pocket will treat these as different URLs. This means that if you’re bad about staying caught up with your Pocket list (like I am), it can be very easy to save duplicate articles, making the situation even worse.

Fortunately I have a solution. I wrote this python script to automate the removal of duplicates of entries in your pocket list.

Currently this script works by removing ALL text after a question mark (?) or a hash mark (#) in each Continue reading

Remove Duplicates from Pocket List

One problem I’ve noticed with my Pocket list is that my reading list contains quite a few duplicate entires. Sometimes I forget I saved an article and I save it multiple times, or maybe I save it across-sources (like Twitter or Facebook, or just browsing. It looks like Pocket has some protective capabilities around this. If I endlessly spam the button provided to me by my Pocket chromecast extension, Pocket only saves the one copy and all is good.

Remove Duplicates from Pocket List

One problem I’ve noticed with my Pocket list is that my reading list contains quite a few duplicate entires. Sometimes I forget I saved an article and I save it multiple times, or maybe I save it across-sources (like Twitter or Facebook, or just browsing. It looks like Pocket has some protective capabilities around this. If I endlessly spam the button provided to me by my Pocket chromecast extension, Pocket only saves the one copy and all is good.

DDoS Packet Forensics: Take me to the hex!

A few days ago, my colleague Marek sent an email about a DDoS attack against one of our DNS servers that we'd been blocking with our BPF rules. He noticed that there seemed to be a strange correlation between the TTL field in the IP header and the IPv4 source address.

CC BY 2.0 image by Jeremy Keith

The source address was being spoofed, as usual, and apparently chosen randomly, but something else was going on. He offered a bottle of Scotch to the first person to come up with a satisfactory solution.

Here's what some of the packets looked like:

$ tcpdump -ni eth0 -c 10 "ip[8]=40 and udp and port 53"
1.181.207.7.46337 > x.x.x.x.53: 65098+  
1.178.97.141.45569 > x.x.x.x.53: 65101+  
1.248.136.142.63489 > x.x.x.x.53: 65031+  
1.207.241.195.52993 > x.x.x.x.53: 65072+

$ tcpdump -ni eth0 -c 10 "ip[8]=41 and udp and port 53"
2.10.30.2.2562 > x.x.x.x.53: 65013+  
2.4.9.36.1026 > x.x.x.x.53: 65019+  
2.98. Continue reading

Open vSwitch performance monitoring

Credit: Accelerating Open vSwitch to “Ludicrous Speed”
Accelerating Open vSwitch to "Ludicrous Speed" describes the architecture of Open vSwitch. When a packet arrives, the OVS Kernel Module checks its cache to see if there is an entry that matches the packet. If there is a match then the packet is forwarded within the kernel. Otherwise, the packet is sent to the user space ovs-vswitchd process to determine the forwarding decision based on the set of OpenFlow rules that have been installed or, if no rules are found, by passing the packet to an OpenFlow controller. Once a forwarding decision has been made, the packet and the forwarding actions are passed back to the OVS Kernel Module which caches the decision and forwards the packet. Subsequent packets in the flow will then be matched by the cache and forwarded within the kernel.

The recent Open vSwitch 2014 Fall Conference included the talk, Managing Open vSwitch across a large heterogeneous fleet by Chad Norgan, describing Rackspace's experience with running a large scale OpenStack deployment using Open vSwitch for network virtualization. The talk describes the key metrics that Rackspace collects to monitor the performance of the large pools of Open vSwitch instances.

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Time For A Data Diet?

I’m running out of drive space. Not just on my laptop SSD or my desktop HDD. But everywhere. The amount of data that I’m storing now is climbing at an alarming rate. What’s worse is that I often forget I have some of it until I go spelunking back through my drive to figure out what’s taking up all that room. And it’s a problem that the industry is facing too.

The Data Junkyard

Data is accumulating. You can’t deny that. Two factors have lead to this. The first is that we now log more data from things than ever before. In this recent post from Chris Evans (@ChrisMEvans), he mentions that Virgin Atlantic 787s are generating 500GB of data per flight. I’m sure that includes telemetry, aircraft performance, and other debugging information that someone at some point deemed crucial. In another recent article from Jacques Mattheij (@JMattheij), he mentions that app developers left the debug logging turned on, generating enormous data files as the system was in operation.

Years ago we didn’t have the space to store that much data. We had to be very specific about what needed to be Continue reading

Python and MySQL

Let me preface this post by stating I am not a database expert. I use them occasionally now and then. The below post probably doesn’t show best practices. If you have any suggestions feel free to comment. Over the weekend I’ve been testing various ways for me to store, update, and retrieve data from a […]

Infographic: SDN’s Pulse Among Service Providers

Infographic: SDN's Pulse Among Service Providers


by Steve Harriman, VP of Marketing - January 6, 2015

As Howard Baldwin recently wrote in InfoWorld, the lure of new enterprise technology is great, but then comes the inevitable uncertainty about how in the world to manage it. The backdrop for his comment is the service provider survey we conducted last month at the SDN/MPLS International Conference in Washington, D.C.  As the infographic below shows, production deployment of SDN is way up among service providers, but nearly all are concerned about management.

Baldwin concludes his article by pointing out that although SDN holds great promise for automating and managing WAN operations, traditional management tools, processes, and standards will not work. The good news, he says, is that “…IT is not only being liberated from hardware-specific configuration, it’s also being liberated from hardware-specific management. In other words, you’ll be able to manage devices the way you want to, not the way the application dictates.”

Right now that’s more of a hope than a concrete solution. At Packet Design, we have made some headway on our concept of a Network Access Broker. See our conceptual demo here: http://www.packetdesign.com/blog/network-access-broker-conceptual-demo

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