[systemd-devel] nss-mymachines: slow name resolution

[Kai Krakow]

Am Tue, 16 Feb 2016 19:39:26 +0100
schrieb Kai Krakow <hurikhan77 at gmail.com>:

> Am Tue, 16 Feb 2016 15:35:24 +0100
> schrieb Lennart Poettering <lennart at poettering.net>:
> 
> > On Mon, 15.02.16 21:32, Kai Krakow (hurikhan77 at gmail.com) wrote:
> > 
> > > Am Mon, 15 Feb 2016 14:28:19 +0100
> > > schrieb Lennart Poettering <lennart at poettering.net>:
> > > 
> > > > On Sun, 14.02.16 13:49, Kai Krakow (hurikhan77 at gmail.com) wrote:
> > > > 
> > > > > Hello!
> > > > > 
> > > > > I've followed the man page guide to setup mymachines name
> > > > > resolution in nsswitch.conf. It works. But it takes around 4-5
> > > > > seconds to resolve a name. This is unexpected and cannot be
> > > > > used in production.
> > > > 
> > > > This sounds like the LLMNR timeout done. I figure we should fix
> > > > the docs to suggest that "mymachines" appears before "resolve"
> > > > in nsswitch.conf. That should fix your issue...
> > > 
> > > Apparently it doesn't fix it - although I will leave it in this
> > > order according to your recommendation.
> > > 
> > > Is there a way to globally disable LLMNR altogether to nail it
> > > down? I tried setting LLMNR=false in *.network - didn't help.
> > 
> > Use the LLMNR= setting in /etc/systemd/resolved.conf
> 
> Yeah! *thumbsup* You da man, Lennart!
> 
> Setting LLMNR to "resolve" or to "no" globally solves the problem
> which proves your first suspicion.

BTW: Enabling and starting avahi also fixed the problem (at least it
looks like, did a few other steps), although I don't see it listening
on port 5353.

> Now, how can I figure out which interface is the problematic one? Do I
> actually need LLMNR in a simple home network?
> 
> The long term is to use this in a container based hosting environment.
> I'm pretty sure I actually don't need LLMNR there. So I'm just curious
> how to "optimize" my home setup.


-- 
Regards,
Kai

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