Networking Field Day 8 #NFD8


The folks at Gestalt IT are putting on yet another Networking Field Day event in Silicon Valley. You can follow the hash tag #NFD8 on Twitter and/or watch the live video streams at



Digital Ocean – DNS Issues & Kernel Issues


Here's a short story, partially still in progress. With all the security breaches going on I thought for a few moments that I might have been caught up in one of them. This past Thursday night I noticed that both my virtual servers, which are hosted by Digital Ocean, were very slow to login via SSH, I mean extremely slow on the order of 8 to 10 seconds. Accessing the WordPress installation on one of those virtual servers was also extremely slow. I began to fear that one of my servers had fallen victim to some vulnerability or exploit and […] Read More


Akamai CDN and TCP Connections


In my latest adventure I had to untangle the interaction between a pair of Cisco ACE 4710s and Akamai's Content Distribution Network (CDN) including SiteShield, Mointpoint, and SiteSpect. It's truly amazing how complex and almost convoluted a CDN can make any website. Any when it fails you can guess who's going to get the blame. Over the past few weeks I've been looking at a very interesting problem where an Internet facing VIP was experiencing a very unbalanced distribution across the real servers in the severfarm. I wrote a few quick and dirty Bash shell scripts to-do some repeated load tests […] Read More


Web Application Load Testing – TCP Port Exhaustion


I recently ran into an puzzling issue with a web framework that was failing to perform under a load test. This web framework was being front-ended by a pair of Cisco ACE 4710 Application Control Engine (Load-Balancer) using a single IP address in a SNAT pool. The Cisco ACE 4710 was the initial suspect, but a quick analysis determined that we were potentially experiencing a TCP port exhaustion issue because the test would start failing almost at the same point every time. While the original suspect was the Cisco ACE 4710 it turned out to be a TCP port exhaustion […] Read More


Response: Scripting Does Not Scale For Network Automation


About three weeks ago Greg Ferro from Etherealmind posted an article entitled "Scripting Does Not Scale For Network Automation". It's quite clear from reading the article that Greg really is "bitter and jaded".  While I agree that there are challenges in scripting they also come with some large rewards for those that are able to master the skill. In a subsequent comment Greg really hits on his point.. "We need APIs for device consistency, frameworks for validation and common actions. But above that we need platforms that solve big problems - scripting can only solve little problems. " I agree […] Read More

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