Debug output is usually obtained through the serial port (ASY0) or via telnet on the router (not SSH). The options are: "debug 0" -> ASY0 "debug 1" -> ASY1 "debug t" -> TELNET To obtain debug output through SSH connect to the router via an SSH client & log in: Now, from the command line run the CLI command "TELNET 127.0.0.1" & log in: Now, you can send the debug output to the Telnet port running the CLI command "debug t" to see the debug output: Following an example in which IKE debug is enabled with level 4 (very high) and a IPsec VPN is removed: NB: In order to be sure to have all the debug output without losing old logs, please assure that the scroll line limit of the SSH client is high (for example 2000). In Putty for example you should go to Change settings > Window to change the “Lines of scrollback” value: .