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

[Reinhard Tartler]

Sjoerd Simons <sjoerd at spring.luon.net> writes:

> 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.

So your point is that you want to have debian still being able to 'see'
unicast dns lookups with having libnss-mdns enabled. Hmm. tricky. 

>> >> 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 

I think I don't understand your proposal then. Let's take my laptop: I
don't have a local nameserver in my resolv.conf, so there is no point in
waiting for a timeout. /etc/resolv.conf is likely to have nameserver,
which I set manually or has the last nameserver I got via dhcp. Now with
multiple interfaces, it seems to me that you want to try to reach the
nameserver after the first non 'lo' devices comes up. What if the
interface cannot reach the nameserver, because it is reachable only via
an interfaces, which comes up later?


Sjoerd Simons <sjoerd at spring.luon.net> writes:
> Oh, i fully agree that this needs to be fixed. But not by throwing it out
> completely, just by making it work like it should be.
>
> What would be more interesting is what the exact cause for your user is that
> host has this long timeout ? Is this because you just have lo up or you do have
> an interface with a real ip address but no network connectivity or ... ?

The laptop in question is using laptop-net (which seems to work similar
to ifplugd); on bootup there is only 'lo'.

The other usecase with static ips is interesting as well, though.

-- 
Gruesse/greetings,
Reinhard Tartler, KeyID 945348A4