Re: Slow WAN traffic to FreeBSD hosts but not to Linux hosts---how to debug/fix?

From: Matt Garber <matt.garber_at_gmail.com>
Date: Mon, 30 Jan 2023 23:30:00 UTC
> > Any help/insight is gratefully appreciated.
> >
> > Cheers,
> >
> > Paul.
> >
>
> sysctl net.inet.tcp.cc.algorithm=htcp
>
> I would set "htcp" on the server and home computer to improve through in
> your type of situation.



There may be other FreeBSD sysctls that have bad defaults in this scenario
and could be better tuned, but I doubt changing the CC algorithm at this
point is the problem — at least not so much a problem that’s causing
throughput to be reduced so drastically. Happy to be wrong if that does
help things quickly and easily, though.

(Since OP mentioned that FreeBSD CC was set to CUBIC, that would match what
the Linux boxes are using by default, too, unless they’ve been changed to
something newer like BBR… so seems like CUBIC *should* be performing fine
on this WAN link, and the difference is something else.)


—Matt