On Mon, 11 Aug 2014, harshavardhan Reddy wrote: > Is the portscan protection is provided in netBSD..?
See pkgsrc's net/iplog or security/portsentry packages. Also net/snort can be configured to detect some port scans. Also see http://www.openwall.com/scanlogd/ (but I don't see it in pkgsrc). You can probably also setup NPF (or the other packet filters) to detect certain flags and do logging based on the matches.
