OPNsense vs scanlogd

OPNsense is an open-source firewall and routing platform based on FreeBSD, available for self-hosted, web, and API use. Its stateful firewall supports IPv4 and IPv6 and provides live views of passed and blocked traffic. VPN integrations include IPsec, OpenVPN, Tinc, and WireGuard. CARP supports automatic hardware failover with state synchronization, and inline intrusion prevention uses Suricata with Proofpoint Emerging Threats Open rules. The modular Model View Controller framework supports extensions and API functionality. Authentication options include LDAP, Active Directory, RADIUS, captive portal authentication, and 802.1X through a plugin. Community Edition is free at free under the 2-clause BSD license, and installation is limited to x86-64 architecture. Official setup guides cover AWS images, OVA images, and an Azure Virtual Appliance. Business subscriptions add commercial features and support; listed prices are €149 a year or €399 a year for three years. The project began in 2014 as a fork of pfSense and m0n0wall, with its first official release in January 2015.

scanlogd is a free TCP port scan detection tool for Linux and self-hosted deployments. It captures packets through Linux raw sockets, libnids, or libpcap. The project advises against using libpcap alone when fragmented IP packets matter, recommending libnids for non-Linux systems or monitoring an entire network. The official download page lists release 2.2.8, release files and signatures, an Openwall archive, and source browsing through GitHub. scanlogd is listed in Owl, Debian GNU/Linux, Gentoo Linux, ALT Linux, and OpenWrt, with ports in OpenBSD and FreeBSD collections. A contributed precompiled Win32 build is also linked. The project describes scanlogd as designed to be totally safe to use and points readers to its manual page and a Phrack article. Openwall offers commercial configuration, compilation, and installation support at US $250/hour with a six-hour minimum or US $9,000/week; fixed-price quotes are available for sufficiently specific projects.