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

From: Pete French <>
Date: Wed, 01 Feb 2023 12:18:49 UTC
> > In my opinion HTCP is a better default for the current state of the internet.
> It looks like they already changed the default from NewReno to CUBIC in FreeBSD-CURRENT.

This worries me, because I did some experimentatiion yesterday, changing these
settings and trying things out, Not for sending, but for recieving. i.e. I
switch the algorithm on the server, and then send a lot of data to it.

I have a MacBook, on home lan+wifi, and a small server running FreeBSD 13.
I backup the laptop by rsyncing to the server and I can run that manually,
so its a nice test of how fast I can push data to the server.

I switched the server to cubic - and my rsync fails. Not always at the
same point, but predictably after a number of minutes it always fails with the
connection being dropped. Doesnt happen with newreno, and always happens with
cubic. Which surprised me.

So, I switched cubic back to newreno - but if this is going to be the
default in CURRENT then probably we need to gte to the bottom of it somehow. I
just am not sure how to start...