#573 Time Machine Periodically Fails due to authentication issue

[Kevin Hanson]

Hi There,

I'm having an issue on the most recent FreeNAS release, 9.2.1.6-RELEASE, which has netatalk 3.1.2. My MacBooks are all set to back up via Time Machine with authentication + encryption, and they work great. Then out of the blue, I'll get an error that time machine has failed to back up due to an authentication error. If I go and try to manually force the backup, it usually works, and then it will continue hourly backups for a day or two, and then the same issue again. I've attached my logs. Thanks! May be related to this issue: https://bugs.freenas.org/issues/4808

[Abscond]

I'm also seeing this on FreeNAS 9.2.16/Netatalk 3.1.2. I have two MacMinis and two MacBooks all running Mavericks, and all run into the same problem when attempting to backup to the single FreeNAS box.

[Daniel Markstedt]

Reading the freenas bug report, the root cause is pretty clear: Zeroconf registers the AFP server as ...

afp://user@host._afpovertcp._tcp.local/Time Machine

whereas the macOS keychain stores the credentials for host.local without the afpovertcp piece.

(The bug tracker is offline so the report can be found here: https://web.archive.org/web/20151029045756/https://bugs.freenas.org/issues/4808 )

This string is defined in https://github.com/Netatalk/netatalk/blob/main/etc/netatalk/afp_zeroconf.h

#define AFP_DNS_SERVICE_TYPE "_afpovertcp._tcp"

This makes its way into the mdns and avahi init calls, and then somehow into the server URL. I need to read up on the avahi and mdns docs to understand how this happens.