summary
To enable AirPrint on a printer already connected to an AirPort Express,
install and setup cups (to serve the printer) and avahi (to
theoretically discover the printer and advertise the printer as
AirPrint-capable).
In CUPS, add a printer using “AppSocket/HP JetDirect” with the address
socket://[name-or-IP-of-your-airport-express]:9100.
background
The AirPort Express (MC414LL/A, A1392) has a USB port that can be used to share a printer on the network.
The AirPort will take care of providing and advertising the printer on the network (via Bonjour), but the network printer won’t support AirPrint.
DNS-SD
In the ideal setup, avahi-daemon will detect the printer’s Bonjour
broadcasts, and you can use cups to seamlessly add the printer for
sharing: cups on Debian
already supports AirPrint (thanks to their hard work!).
To detect the printer, we can use lpinfo:
$ sudo /usr/sbin/lpinfo --include-schemes dnssd -v
network dnssd://[printer-name]._pdl-datastream._tcp.local/
In CUPS, you will be able to add the printer as usual, with this address
(dnssd://...), along with drivers and so on, but you won’t be able to
print anything to it.
The advertised printer address is self-assigned (169.254.0.0/16),
which might be why CUPS can’t send jobs to the printer?
$ avahi-browse _pdl-datastream._tcp -t --resolve --no-db-lookup
= eth0 IPv4 [printer-name] _pdl-datastream._tcp local
hostname = [AirPort-Express.local]
address = [169.254.76.153]
port = [9100]
txt = [...]
A reboot of the AirPort will provide the correct address temporarily, but the advertised service eventually reverts to a self-assigned address.
workaround
The fix, which I found documented here, is to add the IP address or name of the AirPort in CUPS:
- browse to
https://[name-or-IP-of-CUPS-server]:631 - Administration -> Add Printer
- Other Network Printers -> AppSocket/HP JetDirect
- Connection:
socket://[name-or-IP-of-your-airport-express]:9100 - finish installation as usual
On an iOS device, try printing something via AirPrint. The printer should automatically show up.