Wierd IDE/IP Masq issues

[Andrew Bartlett]

Paul Bryan wrote:
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> On Sat, 2 Nov 2002 22:47, Geoff Smith wrote:
> > Hi all,
> >
> > I'm getting some really wierd behaviour on my network at home.
> > My desktop machine acts as a gateway for the rest of the machines on the
> > network, just doing basic IP Masquerading using iptables. Whenever I'm
> > either watching a DVD or burning cds on my desktop, my desktop seems to
> > stop forwarding port 80 to other machines on the network. Services like
> > pop email work fine. The moment the cd finishes burning or I turn off
> > the DVD, everything is back to normal.
> > I'm running Red Hat 8 on my desktop. My burner and DVD are both ide
> > drives. DVD is /dev/hdc, burner is /dev/hde.
> > Has anyone seen or heard of this sort of thing before?
> >
> > Cheers,
> >
> > Geoff
> 
> Sounds a little mysterious. What are you using to play DVD's / burning CD's
> with? Have you had a look at netstat when your having the problems, and when
> your not? That might tell you whether something is listening to port 80
> stuff.
> 
> Try to enable logging on iptables and you may see where the packets are
> disappearing to.
> 
> At the very least, you should be able to eliminate some possiblities.
> 
> Also, Have you thought that it may be a coincidence with the CD/DVD issue
> (ie. you've only noticed the problem while doing these things, but it happens
> at other time as well)?

Look into the unmask IRQ setting in hdparm.  I had similar issues - but
it should also affect local services...

Andrew Bartlett

-- 
Andrew Bartlett                                 abartlet at pcug.org.au
Manager, Authentication Subsystems, Samba Team  abartlet at samba.org
Student Network Administrator, Hawker College   abartlet at hawkerc.net
http://samba.org     http://build.samba.org     http://hawkerc.net