Digital Equipment RapidPrint 500, Справочное руководство

Страница: 22 / 192

TCP/IP Concepts
2 - 6
The RapidPrint 500 supports the following MIBs:
The RapidPrint 500 will respond to queries for unknown MIBs with a “not in MIB” error to the
requesting host. See RFC’s 1065, 1066, and 1098 for more information on SNMP queries and the
structure of the MIBs.
NOTE: See Set/Define SNMP for more details.
Traps are sent to a host when an abnormal event occurs on the RapidPrint 500. The RapidPrint 500
can generate limited forms of three of the SNMP traps. It will generate a Coldstart trap when it
first boots, and a Linkup trap when the startupfile (if any) has been read from a host and normal
operation commences. If a startupfile has been configured but the download fails, the RapidPrint
500 will send an Authentication trap. In all three cases, the trap will be directed to the IP address of
the RapidPrint 500’s loadhost. The RapidPrint 500 will not generate traps for cases other than
those listed here.
The RapidPrint 500 has a local SNMP security table to restrict or prevent unauthorized SNMP con-
figuration.
2.5.4 Reverse Telnet (RTEL)
When a server provides a service to a LAT host, the connection is often referred to as Reverse LAT,
in that “normal” LAT connections are logins from the server to a host. Hosts request a Reverse
LAT connection when they wish to access a service, such as a printer or modem, connected to a
server. There was no real standard (or even analogy) for this type of data connection in the TCP/IP
world until now.
To add this functionality to the TCP/IP environment, the RapidPrint 500 comes with special soft-
ware for your UNIX host. Reverse Telnet, much like Digital’s Reverse LAT, provides the software
capability for a UNIX host to initiate connections to the RapidPrint 500. These connections can be
made through a back-end program for a printer, or through a named pipe. For example, you can
print files from your UNIX host to a printer attached to the RapidPrint 500 through your host’s lp
or lpr print system. RapidPrint 500 services do not care what type of hosts are using them. Multi-
ple jobs from any of the supported protocols can be queued up simultaneously on any service.
2.5.5 LPR Support
The RapidPrint 500 and many UNIX systems implement the Berkeley remote printing protocol
(lpr). This protocol makes it very easy to add print hosts to a system. To add the RapidPrint 500 as
a print host, add the server’s IP address to a host table and add the server’s service name as a print
queue. No special host software or other configuration is needed; RapidPrint 500 services can be
accessed via the normal lpr commands on the host.
Print jobs can be forwarded multiple “hops” in the network. If you only want one host to know
about the RapidPrint 500 print queues, all other hosts can be configured to forward their print jobs
to that one host which then forwards them to the RapidPrint 500 for printing.
NOTE: See Chapter 10 , UNIX Host Setup for more information.
MIB-II (RFC 1213): System, Interface, Address Translation, IP, ICMP, TCP, and
UDP. They do not support the EGP group.
Parallel MIB (RFC 1660): All objects (parallel devices).