[avahi] "Unable to locate printer" -- Printer name confusion (bug?)

[Ronald F. Guilmette]

I've been trying, of late, to set up a fresh new FreeBSD system, and to
enable printing therefrom, and so far I've made just about every mistake
that it is possible to make.  (The old saying is that software cannot
be made foolproof because they keep on inventing bigger fools.  In this
case, that would be me.)

Anyway, after much struggle I've managed to get CUPS and the cupsd daemon
up and running, and I've managed to add my specific local networked printer
(Brother MFC-7860DW) to CUPS so that it (CUPS) now knows that it exists as
a printer.  I've also enabled both dbus and the avahi daemon to correctly
start up at boot time.

Now I can print, e.g. from applications like firefox, HOWEVER, those print
jobs are consistantly failing to actually be sent to the printer, and CUPS
is consistantly showing me the following error when I go to look at these
(failed) print jobs via CPUS' in-built web interfacce (http://localhost:631):

	Unable to locate printer "bromance"

I think that I may possibly have figured out the cause of the problem here,
or maybe not.  I'm hoping that you folks will tell me if I have or not.

Quite simply, several days ago, as I was starting this grand adventure, I saw
again something I had seen many times before which was that my networked
printer had an ugly and not very memorable sort of name name which was
showing up in the clients listing on my ASUS router.  The name being shown
was always "BR" followed by some long string of numbers... not very memorable.

So I took it upon myself to change the printer name, via the printer control
panel, to "bromance".  This I apparently did successfully.  Note in particular
the next-to-last line of this output from the bundled "snmp" program that
comes packaged with the CUPS 2.x.x package:

    https://pastebin.com/raw/1zp7GBui

So anyway, bottom line, I do believe that CUPS knows my printer by the name
"bromance" and that it puts things/jobs into its spool along with instructions
that they should ultimately be sent to "bromance".

While trying to debug my printing problem, I stumbled upon this helpful page
which gave me a hint as to how I could find the name that avahi is associating
with my printer's static IP address (192.168.1.57):

    https://bbs.archlinux.org/viewtopic.php?id=92011

I took the hint from that page and ran the following command, which produced
the output shown:

    % avahi-resolve-host-name -a 192.168.1.57
    192.168.1.57    BRN001BA9A2273F.local

>From this I infer that avahi is... for reasons I am none too clear on...
still of the opinion that the correct and proper name for my local networked
printer is actually still "BRN001BA9A2273F".

This, it seems to me, might possibly explain why CUPS is ready, willing, and
able to believe that my local priter is named "bromance" but when it (CUPS)
actually goes to try to actually send a job to that printer, it somehow
loses its mind and can no longer even find the bleepin' thing.

What say you avahi folks?  Is this a plausible explanation for my ongoing
inability to print?

And why is avahi-daemon picking up the (old/original) name for this printer,
even after I have used the printer's control panel to change its name?  And
where is it even getting this old name (BRN001BA9A2273F) from anyway??  That
name  doesn't seem to be being provided as part of any SNMP data, so I am
totally in the dark about where and how avahi is even finding or obtaining
it.

This is all most perplexing.

I guess that I'll probably try and see if I can use the printer's control
panel to switch its name back to BRN001BA9A2273F, and then reboot everything
and try printing again, but if that doesn't work them I'm entirely screwed,
because I don't know what else to even try, and I don't have the first clue
of how to debug any of this any further.

Any and all help will be appreciated.


Reards,
rfg


P.S. I have looked at my /usr/local/ect/avahi/hosts file and there is nothing
in there other than comments.

P.P.S.  I did try running some more test commands, just to ses if I could
maybe figure out what's going wrong here.  Output for those is/was as follows:

    % avahi-resolve-host-name bromance
    Failed to create host name resolver: Invalid host name
    % avahi-resolve-host-name BRN001BA9A2273F.local
    Failed to resolve host name 'BRN001BA9A2273F.local': Timeout reached
    % avahi-resolve-host-name bromance.local
    Failed to resolve host name 'bromance.local': Timeout reached
    % avahi-resolve-host-name BRN001BA9A2273F
    Failed to create host name resolver: Invalid host name