Running an RPi as printer server for years now, but today it suddenly (*) decided not to receive any documents anymore
(*) Tried to print 3 different PDFs. 2 came out - and after that: the local print-queue (on client) piled up, while the CUPS server queue stayed empty.
Strange...
[SOLUTION]
I don't know why, but for some (yet unknown) reason, my DNS (bind9) decided to resolve the printer server's ".local" name to a 169.254.222.xx address. I know those are ad-hoc IPs if no DHCP is present, but no clue why it suddenly resolved to this, instead of the server's actual IP
I restarted the DNS server (running on the same Raspberry as CUPS):
Now the printer server name resolved correctly again, and printing worked. again.$ sudo service bind9 restart
Hmpf.
Not a big fan of auto-configuration in situations where it just should NOT happen, because there is nothing to auto-configure...