Re: Small TCP packets == very large overhead == DoS?

[Pavel Machek <pavel () ucw cz>]

Hi!

> If any of you have tested what happens to the ability of a box to
> perform well when it has a small MTU you will know that setting the
> MTY to (say) 56 on a diskless thing is a VERY VERY bad idea when NFS
> read/write packets are generally 8k in size.  Do not try it on a NFS
> thing unless you plan to reboot it, ok ?  Last time I did this was
> when I worked out you could fragment packets inside the TCP header
> and that lesson was enough for me ;_)

AFAI can remember, there's minimum MTU defined for IP (something like 576)...
...and then there are networks like hamradio that use lower MTU. They are
really non-compliant, but Linux wants them to work.
                                                                Pavel
-- 
Philips Velo 1: 1"x4"x8", 300gram, 60, 12MB, 40bogomips, linux, mutt,
details at http://atrey.karlin.mff.cuni.cz/~pavel/velo/index.html.