On Tue 11 Oct 2016 at 12:19:30 +0200, Daniel Pocock wrote: > On 11/10/16 12:02, Brian Potkin wrote: > > [I made a mistake with my previous mail by not sending it to the BTS. > > Because of that your reply didn't go there either. I've rectified the > > bug record by bouncing both mails to the BTS and setting the addresses > > correctly on this mail]. > > > > > > On Tue 11 Oct 2016 at 09:59:42 +0200, Daniel Pocock wrote: > > > >> On 10/10/16 21:22, Brian Potkin wrote: > >>> > >>> Printing "working fine" for a long time must indicate something to you. > >>> Then it stops working. How is this a bug rather than a matter for > >>> debian-user? Computer systems don't generally go into meltdown because > >>> they feel unappreciated. > >> > >> The bug isn't because it stopped working (I got it working again anyway) > >> > >> I raised a bug because I was hoping we could improve the user experience > >> for people who don't know how to dig around in the log files. Maybe it > >> should be a wishlist bug. > > > > My view would be that with printing problems users have to be prepared > > to dig into log files, particularly the error_log. Without it a user > > will get nowhere -fast. > > > > [...Snip...] > > > > In that case, we really need to anticipate having a GUI for browsing > SysLog in the default desktop. Text based log files are not great for > the average user and even for power users, the text-based log files > don't distinguish errors from warnings or info messages.
GUIs for browsing any logs is a much wider issue than what we have here. The primary source of information for diagnosing problems with the printing system is the error_log. It has good discrimination indicators for error, info etc. I believe Fedora feed it to journalctl so I suppose you get colour too! > >>> This is a symptom indicating you have done something to the system. It > >>> never happened before; why should it happen now? Things don't generally > >>> occur out of the blue. > >> > >> After looking more closely, I believe the root cause was a recent > >> firewall change that was interfering with mDNS. Tweaking the firewall > >> makes it work again. This hadn't been obvious because some other > >> devices had been able to send stuff to the printer and the printer and > >> the printer's web admin pages were accessible. > > > > Is it possible to be a little more specific about the firewall settings > > which blocked mDNS packets? I think that on Fedora SELinux is there by > > default and it is not unknown for it to cause a misconfiguration issue > > such as the one you have experienced. However, I have not seen it on > > Debian so knowing what you did would be a useful jumping off point for > > documentation. > > In this case, Shorewall had been installed with a very basic configuration > > Adding this entry to /etc/shorewall/rules in SECTION NEW: > > > > SECTION NEW > > mDNS(ACCEPT) loc fw > > > > made it work. Thank you for this; it gives me something to work on. Incidentally, hp-setup GUI and hp-probe suggest examining firewall settings if a printer is not detected. Cheers, Brian.
