[SunRescue] Re: Help!

Sebastian Marius Kirsch rescue at sunhelp.org
Fri Apr 20 10:19:17 CDT 2001


On Fri, Apr 20, 2001 at 03:15:18PM +0100, Paul Sladen wrote:
> > You also can't get enough performance out of a 486 any more for anything
> > more than a dial-up connection anyway, particularly if you want to do
> > any serious amount of IP filtering, NAT, etc.  I ran my cable modem
[...]
> a) biggest load on my 486sx25 router is starting up the perl script to
>    update the dynamic DNS

In my experience, for home users the problem is not routing per se, but
the PPPoE protocol some of us unfortunate DSL subscribers are stuck
with. The rp-pppoe daemon can easily bring a 486DX or a sun4c SPARC to
its knees. (My IPX with powerup won't do more then 50KB/sec over my
768kbps DSL line.) I don't know how that thing manages to suck up so
much power, but it does; and it's not only user time either -- according
to top, it's about 1/3 user time and 2/3 system time. (The pppoed runs
in user space, but uses bpf.) What's really curious about this is that
switching the normal 40MHz processor with a 80MHz powerup didn't change
anything -- throughput is still stuck at 50KB/s.

But NetBSD is getting in-kernel PPPoE now, so this will probably get
better soon. (You should be able to synchronous PPP with in-kernel PPPoE
too -- with the rp-pppoe package, you can only do asynchronous PPP,
which sucks up even more time.)

-- 
Yours, Sebastian Kirsch <skirsch at moebius.inka.de>

Mathematics deals exclusively with the relations of concepts
to each other without consideration of their relation to experience.



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