Mbuf Clusters on 4.8

[John Bäckstrand]

> > >From this it sounds as it is a problem that should
be
> > fixed, but it
> > obviously isnt in 4.8. Is this behaviour now
considered
> > acceptable? And if
> > so, doesnt this make FreeBSD extremely easy to kill
> > using a simple
> > DOS-attack? Is this "fixed" in any way on 5.1?
>
> Yup, that is what DoS attack is... exhaustion of one
or more resources
> of the victim.
>
> P2P software is an easy way to exhaust mbuf buffers
on a box.  P2P
> software(e.g. edonkey) can be a useful network stress
tool; opens lots
> of connections and pushes a lot of data.  My
experience with mbuf
> exhaustion on a 4-stable boxes has been the box
basically loses network
> connectivty until it can recover some buffers.  The
box is still
> responsive from the console and killing the offending
application from
> the console will free up the mbufs and restore
network connectivity.

Ah, unfortunately my box doesnt respond even to
keyboard events (caps lock etc). The behaviour you
describe I find totally acceptable on the other hand.
And the software Im writing happens to be p2p-related,
but its not a edonkey server. :)

---
John Bäckstrand