Debugging Procedure for SIP Over UDP

For detailed information about the Kernel Debug, see the R80.40 Quantum Security Gateway Guide.

The most important information here, are the debug modules and debug flags.

Step

Action

Description

1

Prepare the kernel debug options.

# fw ctl debug 0

# fw ctl debug -buf 8200

# fw ctl debug -m fw + conn drop vm nat xlate xltrc mgcp sip

Best practice:
Enable the 'ld' flag in the 'fw' module. This does, however, cause extremely high CPU load.

2

Verify the kernel debug options.

# fw ctl debug -m fw

3

Start the kernel debug.

# fw ctl kdebug -T -f > /var/log/debug.txt

4

Start the traffic capture in another shell.

# fw monitor -e "host(X.X.X.X), accept;" -o /var/log/fw_mon.cap

5

Replicate the issue.

 

6

Stop the kernel debug.

Press CTRL+C.

# fw ctl debug 0

7

Stop the traffic capture in another shell.

Press CTRL+C.

8

Collect the debug output files.

/var/log/debug.txt

/var/log/fw_mon.cap