If you observe FastNetMon Advanced suddenly stopping to work without any error messages in /var/log/fastnetmon/fastnetmon.log, it may be a crash due to a segmentation fault (segfault) error type.
You can confirm it by running this command:
sudo dmesg
And then checking the output for records like this:
Jul 18 17:21:41 monitor kernel: fastnetmon[30157]: segfault at 0 ip 0000000000445d2f sp 00007f832d861270 error 4 in fastnetmon[400000+90000]
It means some traffic or event caused FastNetMon to execute an incorrect memory operation.
In some cases, you may see records like this in /var/log/fastnetmon/fastnetmon.log:
[ERROR] Previous run crashed, you can find stack trace below [ERROR] 0# 0x00000000004831CE in /opt/fastnetmon/app/bin/fastnetmon 1# 0x00007FBF95594F10 2# 0x00007FBF9C36C817 3# 0x00007FBF95594F10 4# 0x000000000064F03D in /opt/fastnetmon/app/bin/fastnetmon 5# 0x000000000065D09E in /opt/fastnetmon/app/bin/fastnetmon 6# 0x000000000084519C in /opt/fastnetmon/app/bin/fastnetmon 7# 0x000000000084A48F in /opt/fastnetmon/app/bin/fastnetmon 8# 0x000000000084A8BF in /opt/fastnetmon/app/bin/fastnetmon 9# 0x000000000084B3D5 in /opt/fastnetmon/app/bin/fastnetmon 10# 0x000000000084BD13 in /opt/fastnetmon/app/bin/fastnetmon 11# 0x00007FBF9C582095 12# 0x00007FBF9C3616DB 13# 0x00007FBF9567761F
Such entries confirm the segfault error type as well. In such cases, FastNetMon was able to intercept the error and save basic information, which may help in investigating it.
In addition to writing such information, FastNetMon installer enables process memory core dumps, and they can be found in the folder /var/log/core_dumps. They have a name in the format core.*.*.
You can use them to find out more information about a particular crash:
sudo gdb /opt/fastnetmon/app/bin/fastnetmon /var/log/core_dumps/core.... <replace by path to latest core dump file>
After it finishes loading, it will open an interactive command line console, and then you need to run the following command followed by Enter:
bt
It will show a long list of entries, and you need to share it with our support team. We will be able to review the source code, find out the root cause and address it.