In the same directory, download the pfSense-CE-2.5.1-RELEASE-amd64.iso.gz.sha256 file.
If you must use it, the official Netgate archive at atxfiles.netgate.com is your only safe harbor. Keep it behind a double-NAT or isolated from the raw internet if possible. And for goodness' sake, turn off "Allow DNS server list to be overridden by DHCP" unless you want DNS leaks. Pfsense 2.5.1 Download Iso
Get-FileHash .\pfSense-CE-2.5.1-RELEASE-amd64.iso.gz -Algorithm SHA256 In the same directory, download the pfSense-CE-2
But why are thousands of sysadmins still searching for "pfSense 2.5.1 download iso" every single month? And for goodness' sake, turn off "Allow DNS
Here is everything you need to know about finding, verifying, and installing pfSense 2.5.1 safely. Released in early 2021, pfSense 2.5.1 was a reactive release. The original 2.5.0 release had significant growing pains, particularly with the move to FreeBSD 12.2-RELEASE and the introduction of Unbound as the primary DNS forwarder.