3 ms·

> On the other hand printers are working on your smartphones but not on your Linux desktop. Ever thought why that is? That's not the case though. The only issu

by franga2000 5y ago

> On the other hand printers are working on your smartphones but not on your Linux desktop. Ever thought why that is? That's not the case though. The only issues I've had were: 1. missing drivers (a universal issue), 2. changed IP after initial config (because the configurator save the IP and not hostname - I've seen this happen on Windows too, 3. incomplete drivers (because the printer doesn't fully adhere to the standards and vendor drivers aren't complete/available) So what do printers have to do with any of this?

cookiengineer 5y ago
> So what do printers have to do with any of this? The original post was about zeroconf, and therefore the later multicast DNS-SD based discovery protocol [1]. Namely aireplay, airport, airprint, airscan based protocols that multicast their functionality and protocols via DNS to the 224.0.0.251 or [ff02::fb] addresses on port 5353. Printers these days do have primarily support for airprint + airscan so they work out of the box on MacOS with all the GUIs that the OS has to offer. Not so much for WSD or other protocols that Linux/Windows still need. CUPS or postscript support usually isn't complete for anything else than TIFF, because nobody seems to give a damn about implementing a PDF rasterizer on-device, let alone gutenprint or postscript/ghostscript support for their scanner devices. Reading through the sibling comments you have to recognize that my interpretation of "what is working" is a different one than a developer's perspective. If someone without programming/linux configuration knowledge cannot print or scan via WiFi, your tool is pretty much useless and didn't replace the 100 fragmented alternatives that existed before it already. My complaints were mostly about avahi's integrated discovery tools like avahi-browse and avahi-discover which are only tools to discover printers, but are themselves useless for printing or scanning on their own (and they're not transport-level libraries for DNS-SD IANA registered protocols either). Literally the only scanning tool that works in the Linux world is "simple-scan" [2], which requires preinstalled "sane-airscan" and an integrated avahi-daemon in the resolv.conf/nsswitch.conf. Don't ask about parallel IPv4 + IPv6 support, because that's totally unsupported and will crash in multiple NAT scenarios the daemon in an endless loop, and is the reason why every Linux wiki will recommend to add "mdns4_minimal" to the /etc/nsswitch.conf file instead of "mdns_minimal". [3] Coming back to my point: I mean, every developer can send a postscript file via bash to an IPP port, but I wouldn't call it a working UX or UI. When comparing the aforementioned shitshow with how everything is nicely working on MacOS, Linux is basically a bad joke when it comes to mDNS support. I mean, the technology is almost 15 years old now, and we still can't have nice printer support on Linux. Using Apple's CUPS as an excuse to say we support printers is a 20 years old excuse. And a deprecated one, btw, because PPD support has been deprecated for years now ... so good luck getting a new printer that works with that. Nonetheless fixing my printer on Linux and debugging what all this stuff is for days inspired me to build a Web Browser that uses mDNS for local peer discovery, so at least something good came out of it. [1] http://www.dns-sd.org/ http://www.dns-sd.org/ [2] https://gitlab.gnome.org/GNOME/simple-scan https://gitlab.gnome.org/GNOME/simple-scan [3] e.g. https://wiki.archlinux.org/title/avahi https://wiki.archlinux.org/title/avahi

cookiengineer 5y ago

> So what do printers have to do with any of this? The original post was about zeroconf, and therefore the later multicast DNS-SD based discovery protocol [1]. Namely aireplay, airport, airprint, airscan based protocols that multicast their functionality and protocols via DNS to the 224.0.0.251 or [ff02::fb] addresses on port 5353. Printers these days do have primarily support for airprint + airscan so they work out of the box on MacOS with all the GUIs that the OS has to offer. Not so much for WSD or other protocols that Linux/Windows still need. CUPS or postscript support usually isn't complete for anything else than TIFF, because nobody seems to give a damn about implementing a PDF rasterizer on-device, let alone gutenprint or postscript/ghostscript support for their scanner devices. Reading through the sibling comments you have to recognize that my interpretation of "what is working" is a different one than a developer's perspective. If someone without programming/linux configuration knowledge cannot print or scan via WiFi, your tool is pretty much useless and didn't replace the 100 fragmented alternatives that existed before it already. My complaints were mostly about avahi's integrated discovery tools like avahi-browse and avahi-discover which are only tools to discover printers, but are themselves useless for printing or scanning on their own (and they're not transport-level libraries for DNS-SD IANA registered protocols either). Literally the only scanning tool that works in the Linux world is "simple-scan" [2], which requires preinstalled "sane-airscan" and an integrated avahi-daemon in the resolv.conf/nsswitch.conf. Don't ask about parallel IPv4 + IPv6 support, because that's totally unsupported and will crash in multiple NAT scenarios the daemon in an endless loop, and is the reason why every Linux wiki will recommend to add "mdns4_minimal" to the /etc/nsswitch.conf file instead of "mdns_minimal". [3] Coming back to my point: I mean, every developer can send a postscript file via bash to an IPP port, but I wouldn't call it a working UX or UI. When comparing the aforementioned shitshow with how everything is nicely working on MacOS, Linux is basically a bad joke when it comes to mDNS support. I mean, the technology is almost 15 years old now, and we still can't have nice printer support on Linux. Using Apple's CUPS as an excuse to say we support printers is a 20 years old excuse. And a deprecated one, btw, because PPD support has been deprecated for years now ... so good luck getting a new printer that works with that. Nonetheless fixing my printer on Linux and debugging what all this stuff is for days inspired me to build a Web Browser that uses mDNS for local peer discovery, so at least something good came out of it. [1] http://www.dns-sd.org/ http://www.dns-sd.org/ [2] https://gitlab.gnome.org/GNOME/simple-scan https://gitlab.gnome.org/GNOME/simple-scan [3] e.g. https://wiki.archlinux.org/title/avahi https://wiki.archlinux.org/title/avahi