Once again I find a nifty tool via Darknet. CDPSnarf lets you passively capture CDP packets and see the yummy goodness inside.
For those who don’t know, CDP stands for Cisco Discovery Protocol. It can be used to discover information about neighboring devices. For example, if I am on a Cisco router that has several interfaces and I want to know what is connected on each interface, I can execute ‘show cdp neighbors detail.’ This lovely command will tell me all about those neighboring devices with the following caveats:
- The devices are Cisco devices.
- CDP is enabled
Here is a good overview of CDP.
As the saying goes, “Knowledge is power.” The more we know about the target network, the easier it is to get past the crunchy outer shell and snack on the chewy center.