How do I enable selective acknowledges (rfc2018/SACK) on a fBSD3.3 ?
I can't find anything interesting with "sysctl", nor in the LINT
kernel configuration file, however there's a lot of references to it
on the kernel source files.
I enabled rfc1323 but I believe this doesn't directly activate
elective acknowledges (at least rfc1323 states so).
FreeBSD doesn't support TCP SACK, unfortunately. Luigi Rizzo had
patches that added it for 2.1.0, but they were never committed, and I
couldn't get them to apply correctly after 3.0.