Now, the obvious question is, what can a hacker do with a bunch of Cisco routers at her disposal. You can hardly install an IRC client on them, although it would have some coolness value to it coming into a channel on IRC from a Cisco box. Maybe I ll work on that one later this life, h3X thinks. But you definitely own the infrastructure this particular network runs on. Therefore, you can redirect traffic in any way possibly supported by IOS. You can filter out specific packets and connections, like the syslog traffic going from the printers to the syslog host. This way, nobody would ever notice things happening with the printers. But, on the other hand, a halfway competent admin would surely notice the total absence of messages.

You can also have some serious fun with the routing. Just set some routes on the routers so they point to each other, and watch the packets jump back and forth until one of the boxes gets tired, and while decreasing the time to live (TTL) value on the packet, simply converts it to heat and blows it out of the fan instead of the interface. But again, it doesn t make too much sense. It just causes the administrators to track down the problem and see if they can find it. And you can be pretty sure that even a total moron would eventually figure out that this route does not belong there and start wondering how it got...