LE9 mDNS fails after Milhouse build #1025

craigehicks · December 6, 2017 at 3:57 AM

On RPI3,

Prior to LE 9 Milhouse #1025, ".local" hostnames used to successfully resolve.

However with #1025, 25-Oct-2017: RPi / RPi2 -- Release post (Bump jsoncpp, avahi and nss-mdns)

".local" hostnames no longer resolve, instead getting eg

> ping DESK09.local

ping: bad address 'DESK09.local'

/lib no longer has an entry for mdns_minimal.so.2

and

/etc/nsswitch.conf still has

hosts: files mdns_minimal [NOTFOUND=return] dns

No machine on the network has an explicit ".local" address

".local" hostnames resolved prior to #1025, and problem still exists with #1201

**milhouse** · December 6, 2017 at 5:08 AM

craigehicks did you see this reply?

Also, see this thread as the current behaviour is believed to be correct - it was the previous behaviour which was not correct. The solution is to not use .local.

craigehicks · December 8, 2017 at 2:00 AM

milhouse, yes, I did see those messages. But from what I read, the users had explicitly named their devices with a ".local" hostname.

Or had tried to use subdomains within ".local" Are you saying that ".local" should not be used to reference zero-configured devices on the LAN?

None of my devices have an explicit hostname ending in ".local", but when I reference, or make calls to these devices I append a ".local" suffix to invoke mDNS resolution. This is how I thought mDNS was meant to work.

If this is not how mDNS is mean to work, how should devices on the LAN be referenced?

To me, it looks as though mDNS is not running since Milhouse update #1025 (when jsoncpp, avahi and nss-mdns were updated).

When avahi-daemon is started (or restarted) since #1025, it throws the following WARNING:

Oct 06 19:18:06 LibreELEC01 avahi-daemon[338]: Successfully dropped root privileges.

Oct 06 19:18:06 LibreELEC01 avahi-daemon[338]: avahi-daemon 0.7 starting up.

Oct 06 19:18:06 LibreELEC01 avahi-daemon[338]: WARNING: No NSS support for mDNS detected, consider installing nss-mdns!

Oct 06 19:18:06 LibreELEC01 avahi-daemon[338]: Loading service file /etc/avahi/services/sftp-ssh.service.

Oct 06 19:18:06 LibreELEC01 avahi-daemon[338]: Network interface enumeration completed.

/etc/nsswitch.conf is still configured to run mdns_minimal:

:

hosts: files mdns_minimal [NOTFOUND=return] dns

:

but the file: /lib/libnss_mdns_minimal.so.2 (and other associated files) no longer exists in /lib after Milhouse update #1025,

and the file:/lib/libnss3.so now exists.

So, is mDNS running??

Or, is the default /etc/nsswitch.conf now configured incorrectly??

Or, if ".local" is not meant to be used to refer to zero-configured devices on the LAN, how does one refer to, and connect to, these devices in the future??

**milhouse** · December 8, 2017 at 2:33 AM

craigehicks yes we were aware that fewer nss_mdns shared object libraries were being installed after the nss_mdns bump, but weren't aware it had had an effect on Avahi. I'll run some tests to determine the minimum number of nss_mdns libraries needed to get Avahi to stop whining, and hopefully that will help. Thanks.

I'm not an expert on .local domains so someone else will have to confirm how they are supposed to be used.

**chewitt** · December 8, 2017 at 8:56 AM Official Post

I'm wondering if this is why AirPlay isn't working in master (at least for me) ?

**milhouse** · December 9, 2017 at 12:39 AM

craigehicks can you try #1208 which includes some nss-mdns updates.

craigehicks · December 14, 2017 at 2:00 AM

milhouse I can confirm that ".local" support is now working with #1210 with the full return of nss-mdns updates. Thanks.