During firewall kernel debug with fw ctl zdebug you received less information that expected. You noticed that a lot of messages were lost since the time the debug was started. What should you do to resolve this issue?
During firewall kernel debug with fw ctl zdebug you received less information that expected. You noticed that a lot of messages were lost since the time the debug was started. What should you do to resolve this issue?
To resolve the issue of losing messages during firewall kernel debug, you should redirect the debug output to a file. Using the command fw ctl zdebug -o ./debug.elg ensures that all messages are saved to the file, preventing loss of information due to buffer limitations. Increasing the buffer size is not applicable for zdebug, as it uses a fixed buffer size.
To me it's answer A. fw ctl zdebug is an internal R&D macros to cut corners when developing and testing new features in the sterile environment. It is equivalent to the following sequence of commands: fw ctl debug -buf 1024 fw ctl debug (your options) fw ctl kdebug -f fw ctl debug 0 (Please check https://checkpoint-master-architect.blogspot.com/2017/11/kernel-debug-best-practices-or-why-fw.html) This way, we can't modify buffer on zdebug and so we have to use fw ctl debug (and not zdebug).
your comment is correct, but probably the answer is incomplete and the answer should be about using in this case fw ctl debug/fw ctl kdebug to a file with output to a file through the symbol >
At first I was thinking C, but to output to a file the command is: fw ctl zdebug > /var/log/tmp/fw_ctl_zdebug_drop.txt therefore C and by extension B cannot be correct and D cannot be correct as you cannot adjust the buffer in zdebug as it's fixed to 1024, therefore A is the only possible answer.
zdebug does not allow the user to allocate a buffer. It automatically enables a 1MB buffer. So, this makes option A and D invalid. The only option is to save all information into a file.