Subject: If packet counters in MROUTE MIB ? (RFC2932)

From: Toerless Eckert <[email-masked]>
Date: Sat, 7 Apr 2001 15:43:22 -0700

Can someone explain to me, why there are no per interface
IP multicast packet input/output counters in RFC2932's
IpMRouteInterfaceEntry ? There are Octet input/output
counters in it, but no packet counters.

When i tried to get an answer to this question from the authors,
i was referred to the byte counters available in the interface
MIB (RFC1573, RFC2233, RFC2863), but i do not understand
how i should put IP multicast packet input/output counters
into ifXTable's ifIn/OutMulticastPkts variables, because by default,
the whole interface MIB is supposed to be layer2, or is it not ?

Eg: On an ethernet interface, these counters should count
ethernet level Multicast packets, and on a serial interface,
they should probably not count any packets at all unless there
is some L2 multicast mechanism on the p2p link. Right ? Wrong ?

What if i don't only have IP ? "There's no multicast beside IP
multicast" ? Fine with me, but does SNMP agree ?

Or let me phrase the question differently: If i have a router
that already utilizes the interface MIB counters for layer2
unicast/non-unicast/broadcast/multicast packet counters,
where the heck should IP Multicast packet counters go into if
those are known within the router explicitly ?

Just wondering...

Thanks
	Toerless

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From: Bill Fenner <[email-masked]>
Date: Tue, 10 Apr 2001 10:06:29 -0700

Toerless,

  I talked to Dave Thaler (one of the authors of RFC2932) about this
issue a couple of months ago, and basically there was some confusion
when the MIB was designed about existing and new counters.

  In the context of IPv6, we're revising the IP (and TCP and UDP)
MIB (see http://www.aciri.org/fenner/mibs/v6/).  One of my proposals
was to add all of these IP multicast packet and octet counters to
this revision.

  Bill