The IPsec logs show output from the IPsec daemon. Normal output, successful connections, as well as errors are all displayed here. On pfSense 2.1.x and before, this output is from the racoon daemon. On pfSense 2.2 and later this task is handled by strongswan
Where possible, if a log message contains an IP address of a configured IPsec tunnel, that tunnel’s description is prepended to the log entry.