There used to be these sysctls in older versions of FreeBSD, viz:


now on FreeBSD 12 sysctl reports that these don't exist.

How can I tune the lifetime for TCP/UDP for in kernel NAT?

  • They are still there. Did you forget to load it? ipfw_load="YES" Aug 20, 2021 at 23:43

1 Answer 1


I found the answer. Basically I was looking at the wrong documentation :-)

I'm actually using pf, and equivalent tunables are documented in the pf.conf man pages, under the section for the set command, specifically set timeout in this case.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.