Comment 6 for bug 1099184

This affects me as well, using a Canon MG3250 over WiFi. The printer supports both IPv4 and IPv6, but CUPS is only able to connect to it when it chooses the IPv4 address, which appears to be about 50% of the time.

I was able to work around the problem by going to my printer's web control panel, going to the Network Settings page, and choosing "Disable IPv6". After a few seconds, Avahi (avahi-browse -a -t -r) no longer reports IPv6 support for my printer, and everything works splendidly.

Obviously a fix for Avahi or CUPS would be preferable.

/var/log/cups/error.log shows the following for success:

D [20/Dec/2013:23:05:05 +0000] [Job 1433] Connecting to 192.168.0.16:631
I [20/Dec/2013:23:05:05 +0000] [Job 1433] Connecting to printer.
D [20/Dec/2013:23:05:05 +0000] [Job 1433] Set job-printer-state-message to "Connecting to printer.", current level=INFO
D [20/Dec/2013:23:05:05 +0000] Discarding unused job-progress event...
D [20/Dec/2013:23:05:05 +0000] Discarding unused printer-state-changed event...
D [20/Dec/2013:23:05:05 +0000] [Job 1433] update_reasons(attr=0(), s="-cups-certificate-error")
D [20/Dec/2013:23:05:05 +0000] [Job 1433] update_reasons(attr=0(), s="-connecting-to-device")
D [20/Dec/2013:23:05:05 +0000] [Job 1433] STATE: -connecting-to-device
I [20/Dec/2013:23:05:05 +0000] [Job 1433] Connected to printer.
D [20/Dec/2013:23:05:05 +0000] [Job 1433] Set job-printer-state-message to "Connected to printer.", current level=INFO
D [20/Dec/2013:23:05:05 +0000] [Job 1433] Connected to 192.168.0.16:631...

and the following for failure:

D [20/Dec/2013:23:05:05 +0000] [Job 1433] Connecting to 192.168.0.16:631
I [20/Dec/2013:23:05:05 +0000] [Job 1433] Connecting to printer.
D [20/Dec/2013:23:05:05 +0000] [Job 1433] Set job-printer-state-message to "Connecting to printer.", current level=INFO
D [20/Dec/2013:23:05:05 +0000] Discarding unused job-progress event...
D [20/Dec/2013:23:05:05 +0000] Discarding unused printer-state-changed event...
D [20/Dec/2013:23:05:05 +0000] [Job 1433] update_reasons(attr=0(), s="-cups-certificate-error")
D [20/Dec/2013:23:05:05 +0000] [Job 1433] update_reasons(attr=0(), s="-connecting-to-device")
D [20/Dec/2013:23:05:05 +0000] [Job 1433] STATE: -connecting-to-device
I [20/Dec/2013:23:05:05 +0000] [Job 1433] Connected to printer.
D [20/Dec/2013:23:05:05 +0000] [Job 1433] Set job-printer-state-message to "Connected to printer.", current level=INFO
D [20/Dec/2013:23:05:05 +0000] [Job 1433] Connected to 192.168.0.16:631...

I am using CUPS 1.5.3 on Ubuntu 12.04LTS.