Did PPP incoming-filter change in recent versions?
Where can I find an example of incoming-filter setup? The documentation says that i should look in the Examples section, but examples do not show the filter setup!!
You can specify firewall filter chain name, where input traffic (when it is incoming) will be forwarded. There should be firewall rules in the specific chain, plus you need to add jump to input/forward/output (depends on traffic you want to filter for PPP clients) to chain=ppp to make incoming-filter working.