Cisco source codes never were a top secret, many people around the world had access to them (and I believe, it explains Cisco's stability and success). Rough translation of: http://www.securitylab.ru/45221.html May, 15 2004 Leak of code CiSCO IOS source code? As it became known to SecurityLab, the source code of operating system CISCO IOS 12.3, 12.3t, which is used in the majority of Cisco network devices has been stolen on May 13, 2004. The total volume of the stolen information represents about 800MB in an archive file. According to the information available to us, the leak of fragments of the source code occurred because of a break-in into the corporate network of Cisco System. Representatives of Cisco System have not made any comments about the break-in so far. A person whose alias on *darknet@EFnet IRC is "franz" has given a small parts of the source code (about 2.5 Mb) as proof. Below are links to the first 100 first lines of source code of: ipv6_tcp.c: http://www.securitylab.ru/45222.html ipv6_discovery_test.c: http://www.securitylab.ru/45223.html