Configuring Cisco IOS

To configure a Cisco IOS device to write core files, the device must be able to connect to an FTP server that allows file uploads. This can be an FTP server with anonymous file upload or requiring user authentication.

Configuration

To configure IOS for writing core files, follow the steps below. The core file name should reflect the router's name, so you can distinguish between the routers writing core on your FTP server.
	Router# conf t
	Router(conf)# exception core-file ROUTERNAME
	Router(conf)# exception dump FTPSERVER
	Router(conf)# exception protocol ftp
	Router(conf)# exception region-size 65536
	
If your FTP server requires authentication, you need to configure the username and password additionally:
	Router(conf)# ip ftp username USERNAME
	Router(conf)# ip ftp password PASSWORD
	
Save this configuration by exiting the configuration mode and after testing make sure you store it in the startup-config as well.

Writing Core Files at Runtime

After configuring the router, core files can be written at any time by issuing the following command in a level 15 authenticated (enabled) command line session:

	Router# write core