Re: sysctl options for Maximum segment size

[Hugh Graham <hugh@openbsd.org>]

On Thu, Nov 30, 2000 at 10:53:16AM -0500, kfl wrote:
[html][head][/head][body]Hi all,[br]
[br]
    Just for curiosity, does anyone know why the MSS is set to 512 in
OpenBSD while it's 1460 (ethernet) in FreeBSD?[br]
[br]
Thx in advance,[br]
[br]
Karim.[br]
[/body][/html]

It's set to a conservative value so you can set an openbsd machine down
inside most any network and expect it to work without tweaking. Even with
mss set to 512 bytes the ip+tcp overhead is only roughly 20%. Increasing
this may cut the protocol housekeeping to 7%, but you would then be more
likely to encounter fragmentation or lossage problems in some networks.
Not a good thing to default to.

/Hugh

PS, I ran your attachment through :%!tr '><' '][' so you can see roughly
what html looks like to most of the mailreaders on these lists...