Logging and statistics
To record a log message each time the SIP ALG finds a malformed header, enable logging SIP violations in a VoIP profile. In all cases, when the SIP ALG finds an error the FortiGate records a malformed header log message that contains information about the error. This happens even if the action is set to pass.
If, because of recording log messages for deep message inspection, the CPU performance is affected by a certain amount, the FortiGate records a critical log message about this event and stops writing log messages for deep SIP message inspection.
The following information is recorded in malformed header messages:
- The type of message line in which the error was found.
- The content of the message line in which the error was found (it will be truncated if it makes the log message too long)
- The column or character number in which the error was found (to make it easier to determine what caused the error)