The kernel dumps core for signals that imply a program error. Receipt of an interrupt signal implies that the user wants to prematurely terminate a process, which doesn't imply that anything is wrong; however, the quit signal induces a core dump even though it's initiated outside of the running process.

To obtain a core dump when a (Cisco) router crashes, use the exception dump ip-address config command, where ip address is the address of your TFTP server. Including this command in the config causes the router to attempt to make a core dump when it crashes. It is recommended that you use either RCP or FTP to dump the file to a server, because if you use TFTP, it will only dump the first 16 MB of the file. You can also configure the router to dump core and reboot when defined memory size parameters are violated, with the exception memory commands. If you don't want the router to reboot, you can cause the router to generate a core dump with write core.