[cups] Accessing a parallel printer from a remote network

[Phil Reynolds]

I have an HP LaserJet 6P, working very well within my local network,
but I may sometimes want to print to it from my laptop which is
sometimes on a mobile connection (fixed IP which makes things a bit
easier).

On Debian jessie, cups 1.7.5 is installed (the only OS I am currently
using on physical machines). One way I thought of was to use IPP, but
whenever I try the URL provided by ipp --ls, I find that my laptop
cannot get the printer status, even on the home network where it can
see the shared printer (dnssd/Bonjour is working on the internal
network).

The server logs errors like these when I try to use the printer via IPP:

E [17/Jul/2015:12:47:39 +0100] [Client 17] Request from
"[v1.<IPv6-ADDRESS-REDACTED>]" using invalid Host: field
"<FQDN-REDACTED>:631"

Is there any way I can access the printer using Bonjour off the network
(cups-browsed configuration)? Failing that, why am I finding IPP
unusable?

-- 
Phil Reynolds
mail: phil-cups at tinsleyviaduct.com
Web: http://phil.tinsleyviaduct.com/