PMP Mail Archive: Re: PMP> prtChannelIfIndex

Re: PMP> prtChannelIfIndex

Bill Wagner (bwagner@digprod.com)
Tue, 18 Feb 1997 23:05:27 -0500

Harry,

One argument suggests that only the network node being that the
printer is being viewed through is of interest with respect to network
node infromation. But the status of the printer must include the
effect of every interface to the printer (network or local).

1. If there is more than one NIC, in viewing the printer through
one NIC, the SNMP presentation must be aware of the other NIC to the
same degree that it must be aware of all alternate inputs to the
printer which may affect printer and status. This means the interface
table must identify all interfaces.

2. The view should also be able to identify that the printer is (or
is not) equipped with a second NIC. I think that a MIB-2 interface
table entry is sufficient since this is what is referenceed in the
printer MIB (that is, HR MIB inclusion as a network device seems of
dubious value).

3. It would be unreasonable and of questionable utility to provide
full MIB 2 support for one NIC through the other. This does leave
Interface table rows with nothing but ifIndex, ifDescr, and ifType
populated. Is this a problem?

4. The report on the printer status and capabiltiesm as viewed
through an interfacem should reflect the capabities of the printer
accessible though that interface. What is the trouble youi see with
this?

Bill Wagner, DPI

______________________________ Reply Separator _________________________________
Subject: PMP> prtChannelIfIndex
Author: "Harry Lewis <harryl@vnet.ibm.com>" <harryl@VNET.IBM.COM> at Internet
Date: 2/18/97 4:22 PM

We discovered that many printers can't distinguish between NICs in terms of
ifIndex. AT least one printer can. Should we try to characterize this?

For instance, for the majority of the implementations, does this imply that
services are the same on both NICs? Or, does this imply that, when you walk
the Channel table, you only "see" services appropriate for the NIC "through
which" you are accessing the printer at that time?

I can see how the "one NIC table" could be a practical approach if you think
in terms of "there's a printer... tell me what I can do with it... at THIS
IP address". But, if there were not 100% overlap in services per NIC, and
a query through one NIC shows all the services but all seem indexed to "NIC
1", I can see trouble.

I wasn't sure, by some of the comments, whether or not we have this situation.

Harry Lewis - IBM Printing Systems