Hello! I just took a quick look on the config and on the internal logs. Couldn't be that "f_discreg" is not included in a log path? Another thing that could be is parsing: your "s_net" source will try to parse incoming messages as either BSD or Syslog format. If you've just tested the filter by sending in the message "default send string", then syslog-ng will parse it, which results that MSG macro will not contain "default send string". With trace level logging you can debug how does the message being parsed (-t command line option), and to disable parsing on the source side use the flags("no-parse") option. See an example: [2020-12-03T09:14:51.016256] Incoming log entry; line='default send string' [2020-12-03T09:14:51.016290] Initial message parsing follows; [2020-12-03T09:14:51.016322] Setting value; name='PROGRAM', value='default', msg='0x7f24a8005f30' [2020-12-03T09:14:51.016334] Setting value; name='LEGACY_MSGHDR', value='default ', msg='0x7f24a8005f30' [2020-12-03T09:14:51.016341] Setting value; name='MESSAGE', value='send string', msg='0x7f24a8005f30' Regards, Gabor ________________________________ From: syslog-ng <syslog-ng-bounces@lists.balabit.hu> on behalf of Saqib M <saqib.m@cummins.com> Sent: Thursday, December 3, 2020 1:48 To: syslog-ng@lists.balabit.hu <syslog-ng@lists.balabit.hu> Subject: [syslog-ng] Filter matching not working CAUTION: This email originated from outside of the organization. Do not follow guidance, click links, or open attachments unless you recognize the sender and know the content is safe. Greetings – I have been trying to create a very basic filter that looks up a string in the incoming log. However, it would not match any filter and would go to the default filter. I have tried both match() and message(), neither worked for me. Please let me know if you think I am missing something. Following are the chunks from the syslog-ng.conf source s_net { # All syslog traffic on port 514 - this is direct from network devices. udp(port (514)); network(transport("tcp") max-connections(20000) log_iw_size(100000000) ); # tags("fortigate", "cisco", "default") ); }; filter f_discreg { message("default send string") }; log { source(s_net); filter(f_dlptracker); destination(d_dlptracker); flags(final); }; Here is the log from the test I ran. [2020-12-02T22:00:36+0000] Incoming log entry; source='s_net#0', line='default send string' [2020-12-02T22:00:46+0000] Filter node evaluation result; filter_result='not-match', filter_type='OR' [2020-12-02T22:00:46+0000] Filter rule evaluation result; filter_result='not-match', filter_rule='f_tanium' [2020-12-02T22:00:46+0000] Filter rule evaluation begins; filter_rule='f_palo_alto' [2020-12-02T22:00:46+0000] Filter node evaluation result; filter_result='not-match' [2020-12-02T22:00:46+0000] Filter node evaluation result; filter_result='not-match' [2020-12-02T22:00:46+0000] Filter node evaluation result; filter_result='not-match' [2020-12-02T22:00:46+0000] Filter node evaluation result; filter_result='not-match', filter_type='OR' [2020-12-02T22:00:46+0000] Filter node evaluation result; filter_result='not-match', filter_type='OR' [2020-12-02T22:00:46+0000] Filter rule evaluation result; filter_result='not-match', filter_rule='f_palo_alto' [2020-12-02T22:00:46+0000] Filter rule evaluation begins; filter_rule='f_dlptracker' [2020-12-02T22:00:46+0000] Filter node evaluation result; filter_result='not-match' [2020-12-02T22:00:46+0000] Filter rule evaluation result; filter_result='not-match', filter_rule='f_dlptracker' [2020-12-02T22:00:46+0000] Outgoing message; destination='d_fallback#0', message='2020-12-02T22:00:46+00:00 172.17.236.3 default send string\x0a' Regards, Saqib M Cybersecurity Co-op Global Cybersecurity Technologies Email: saqib.m@cummins.com<mailto:saqib.m@cummins.com> Cummins Inc.