Re: Printing w/ LPR

[turnbull@example.com (Stephen J. Turnbull)]

>>>>> "Mark" == LNJPTYO1 MDARCY01 <LNJPTYO1.MDARCY01@example.com> writes:

    >> and A's hosts.lpd contains
    >> B.sub.top

    Mark> You nailed it on the head. Thanks very much.

Hm.  Good guess, I guess!  Do you in fact have lpd running on both
machines, or does lpr contact the remote lpd directly?

    Mark> Do you happen to know if the entries in the hosts.lpd file
    Mark> must be DNS verifiable names or can they be non-verifiable
    Mark> names residing in the local /etc/hosts file ?

Not having the source online, I don't know.  I would guess from the
slipshod treatment of the authorization issues in my man pages that my
versions of the various lp* utilities simply check the return IP
address in the IP packets against hosts.lpd, and if there is no such
address in hosts.lpd, do a `gethostbyaddr()' on the return IP address.
On my system, this looks in /etc/hosts, then does a simple reverse
name lookup to the nameserver.  This returns a single name which then
is searched for in hosts.{lpd,equiv}.

The search order for `gethostbyaddr()' can be configured (I think,
it's not documented anywhere I can see) via the hosts.conf file:

turnbull:/tmp$ cat /etc/host.conf 
order hosts, bind
multi on

So my guess is that a request from any IP address listed in /etc/hosts
is ok.  After all, if all these Unix services had been designed with
proper attention to security, we wouldn't need firewalls, would we?

Note that my lp* suite and its docs is quite old, coming from a
Slackware 2.x distribution.

-- 
                           Stephen John Turnbull
University of Tsukuba                                        Yaseppochi-Gumi
Institute of Policy and Planning Sciences  http://turnbull.sk.tsukuba.ac.jp/
Tennodai 1-1-1, Tsukuba, 305 JAPAN                 turnbull@example.com
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