Ethernet Terminals, DHCP and printing
Keith Clay
We are considering moving from a serial terminal server to ethernet
terminals served by DHCP. They are ET2000 terminals from ComputerLab
and they have a printer port. Is it possible to set the printers up
so that they can be printed to from the SCO lpd spooler.
keith
Jean-Pierre Radley
The 'D' in DHCP stands for 'Dynamic', so how will you know which printer
resides at which IP address?
--
JP
Karel Adams
"Jean-Pierre Radley" <j...@jpr.com> schreef in bericht news:2001110718...@jpradley.jpr.com...
<very humbly>
I always understood DHCP allocates dynamic IP adresses to
fixed host names. So it would seem to me that there must be a way
to set up a remote printer port associated with a fixed host name,
then leaving the rest to DHCP.
Or?
<remaining yours humbly...>
KA
>
> --
> JP
Tony Lawrence
No, not quite.
However, all is not lost.
First, Visionfs printing only needs a Netbios name- so that would work,
but not for you :-)
Secondly, if you know MAC addresses (and you can always get that info),
you can get the ip address from arp -an and adjust things as
necessary. That aassumes of course that you are on the same lan and
that some other communication causes arp to be there- a ping will do, of
course.
If a particukar user needs printing to go to their lpd server, that's
easy. I've done that sort of thing for printing over the internet where
someone comes in over ssh from who knows where, but a quick shell script
picks up their ip and modifies /etc/hosts with the new info. This
sounds like it might be what your situation needs- only the user needs
access to their printer? If so, define the hosts by name in printcap
and just modify /etc/hosts as they login- watch out for race conditions-
you need to be careful here.
So yes, you can do this. Just takes a little creativity and some
careful scripting.
--
Tony Lawrence
SCO/Linux Support Tips, How-To's, Tests and more: http://pcunix.com
Jean-Pierre Radley
Programs which use TCP/IP can only find a host by its IP number.
The host could have any name, or even several names, but there has to be
a way to convert the names into IP numbers. /etc/hosts is a simple
mapping; DNS is more complicated.
Sp if you give your printing routine a target name, how will that get
changed to a number.
And why use DHCP at all, instead of fixed IP numbers for machines with
printers attached, especially since these machines are going to surely
remain in the same physical location in your offices, and not move to a
different floor or a different building.
--
JP
Brian K. White
"Jean-Pierre Radley" <j...@jpr.com> wrote in message
news:2001110718...@jpradley.jpr.com...
well, of course you know that dhcp can be used to serve the same ip to the
same mac every time.
it would be about 30% useful IMO. it would make installing new machines as
simple as plugging in a radio to the electricity, but then it requires that
the dhcp server never break. if they use sco's built in server that might be
pretty reliable, perhaps something like almost as reliable as the sco box as
a whole.
and to answer the question...
the answer can only be obtained by the terminal manual.
does the terminal have a built in print server? probably it does. if it
does, then the answer is yes, no problem.
even if the terminal has no built-in print server (highly unlikely) there is
still a possibility that it's terminal emulation includes passthru print
codes, in which case the answer is no, or yes in a severely limited fashion:
you could have scripts and programs that say "blah blah blah |lp" (and it
would come out on the users own printer) but you could not have "blah blah
blah |lp -djoesdesk"
probably they do have built in print servers, and if they don't then you
should look at other terminals because most ethernet terminals do and it'd
be dumb to live without it.
--
Brian K. White -- br...@aljex.com -- http://www.aljex.com/bkw/
+++++[>+++[>+++++>+++++++<<-]<-]>>+.>.+++++.+++++++.-.[>+<---]>++.
filePro BBx Linux SCO Prosper/FACTS AutoCAD #callahans Satriani
Tony Lawrence
> And why use DHCP at all, instead of fixed IP numbers for machines with
> printers attached, especially since these machines are going to surely
> remain in the same physical location in your offices, and not move to a
> different floor or a different building.
Well, because there's more to DHCP than just assigning IP addresees.
There's a LOT of stuff that can be assigned, including default gateways
and DNS info- stuff that's annoying and time consuming to put in
initially and to change if necessary. I'm mostly thinking of Windows
here of course.
Bill Campbell
...
>Well, because there's more to DHCP than just assigning IP addresees.
>There's a LOT of stuff that can be assigned, including default gateways
>and DNS info- stuff that's annoying and time consuming to put in
>initially and to change if necessary. I'm mostly thinking of Windows
>here of course.
DHCP can also assign fixed IP address based on the MAC address of the
terminals using the ``host'' declarations. Here's the one I have on our
internal network to assign a fixed IP address to my laptop.
host tp600.mi.celestial.com {
hardware ethernet 00:10:7A:60:0D:FF;
fixed-address 192.168.253.24;
}
I often get lazy, and get the MAC address from the syslog file when a new
device is first booted. It's a lot easier than reading the tiny numbers on
the back of the terminal.
Bill
--
INTERNET: bi...@Celestial.COM Bill Campbell; Celestial Software LLC
UUCP: camco!bill PO Box 820; 6641 E. Mercer Way
FAX: (206) 232-9186 Mercer Island, WA 98040-0820; (206) 236-1676
URL: http://www.celestial.com/
The pinnacle of open systems is: when moving from vendor to vendor, the
design flaws stay the same.
Simon Hobson
(in message <2001110718...@jpradley.jpr.com>):
Two ways round it :
1) Use fixed addresses but distribute them with DHCP.
This may sounds pointless, but DHCP will configure more than just the
address. It just means that you have to add a static address entry to DNS and
the DHCP config when you add a new device (I used to do that at work until I
found a fully functional dhcp server).
2) Use DHCP with dynamic DNS updating.
Address management is automatic, but DNS is automatically updated. The DHCP
server bundled in SCO Openserver does not do this, I suggest you trot off to
www.isc.org and look at their dhcp server which does (it does an awful lot
more as well). Configure the print system by dns name, and all should work
nicely.
Simon