Bug#409513: [Pkg-utopia-maintainers] Bug#409513: ifup and ifdown slow becouse of avahi-deamon script

[Sjoerd Simons]

On Wed, Feb 21, 2007 at 04:08:01PM +0100, Reinhard Tartler wrote:
> sjoerd at spring.luon.net (Sjoerd Simons) writes:
> > A second one could be done if resolvconf isn't available is to only
> > recheck when avahi is actually disabled, although this assumes that
> > the changes caused by bringing an interface down will never cause an
> > nameserver to be added which has a .local.
> 
> Why do you need this check anyway? If there is an authoritative
> nameserver for .local, what bad happens besides lookups for .local
> address break?

With newer versions of mdns it is indeed the case that only explicit .local
lookups will fail.. With older version all hostname lookups would fail iff you
had local in your search.

So while the situation has improved, it's still quite bad to break networks
this way by having mdns lookups overshadow normal unicast dns lookups.

> >> On Ubuntu the network interfaces are bought up in the background so it
> >> doesn't cause any delays I beleive Debian still does this in the
> >> foreground however, perhaps we can affect the timeout value of 'host'?
> >
> > Well, manually running ifup on ubuntu also does it in the foreground. But
> > yes, ifup -a on startup on debian is done in the foreground. Some things
> > which could be done to optimize this are to _not_ run host when: *
> > /etc/resolv.conf doesn't list any nameservers * only lo is up and 127.0.0.1
> > isn't in /etc/resolv.conf
> >
> > This helps as host will query localhost (and waits untill the queries timeout)
> > when there are no nameservers specified. 
> 
> Errr, I think you assume here that there is only one interface, and that
> one can always reach a nameserver. This is wrong for

I don't assume any of these things. Would be interesting to know why you think
this? The only thing i assume is that if you don't have localhost as nameserver
and only lo is up OR if you have specified no nameservers then you can never
have something authorative for .local using normal dns 

  Sjoerd
-- 
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