[j-nsp] Monitoring interface counters on J/SRX

[Dale Shaw]

Hi,

[ disclaimer: I don't claim to be a network management expert but I
can spell SMTP* ]

In our network, we capture, graph and report on the usual set of
interface counters - errors and discards in/out, octets in/out,
packets in/out and so on. Most of the in-house skills are with Cisco
products but we're getting a lot better with J.

I'm trying to come to terms with the difference between the physical
(ifd) counters and the logical (ifl) counters for both 'family inet'
and 'family ethernet-switching' interfaces.

I'm facing a few dilemmas;
1) on Ethernet interfaces shaped to sub line rate, only logical units
report the 'correct' bandwidth so in order for our graphs to scale
correctly we either have to perform interface utilisation reporting
against the logical unit(s), or manually configure our NMS with the
shaped/provisioned bandwidth value. In most cases we're only using one
logical unit (unit 0).
2) I noticed recently that our NMS is collecting error/discard
counters from logical interfaces, and these appear to be always zero.
A few CLI checks around the network seem to prove the theory -
error/discard counters must be collected from the physical interface.

What's the "right" thing to do here? If there is no right/wrong, what
works for you?

Anyway, I suppose what I'm really looking for is some generic advice
on how to monitor interfaces in Juniper routers and switches -- are
the standard MIBs OK? I just noticed there appear to be interface
counters in jnxMibs. Do you grab interface error/discard counters from
the physical only? Is there a way to populate logical interface
error/discard counters with the underlying physical interface's
counters? (it seems the logical interface does not track
errors/discards, which I guess makes sense).

More than happy to be pointed at good documentation.

Cheers,
Dale

* That was a hilarious joke.