To celebrate the release of Version 7.0 of Scrutinizer NetFlow and sFlow Analyzer, which is absolutely free, I thought I’d share with you three fabulous free resources for Cisco network administrators. Read more »

Distributed denial of service (DDoS) attacks are unfortunately par for the course on the Internet these days but when high-profile sites are targeted, the attacks are big news. Take for example last week’s DDoS attack on Twitter, which the microblogging site speculated was geopolitical in motivation.

Quick overview of DDoS

DDoS attacks are often caused by botnets flooding Web sites with requests thus bringing the site’s Web servers to their knees. A botnet is a collection of computers that have been compromised by viruses and worms so that they can be controlled by malicious individual(s). An example could be the collection of computers compromised by Conficker, however a Conficker botnet has yet to be leveraged to do harm.

In the case of Twitter, the irony is that it could have been the compromised computers of some of Twitter’s own users that caused the DDoS. Read more »