pfSense 2.3.1 shouldn’t be confused with the tiny pfSense 2.3 Update 1 patch, as the former is a major update introducing over 100 changes for most of its components, including the configuration upgrade, gateways support, the backend, the web-based interface, IPsec support, DNS Resolver, and DHCP Server. pfSense 2.3.1 is also about security fixes, in particular for the OpenVPN and OpenSSL packages, as well as FreeBSD’s sendmsg and atkbd tools.