Subject: Re: <draft-ietf-disman-remops-mib-03.txt>

From: Alan Luchuk <[email-masked]>
Date: Wed, 17 Feb 1999 11:48:44 -0500 (EST)

> I think this depends on whether there is a management application that
> periodically polls the results and/or relies on a notification to
> be sent when a ping fails to detect when a network resource becomes
> unavailable. I think it would be useful to define a notification in the
> ping MIB to report when a ping fails. Should the notification be sent
> every time a probe fails? Just the first time or periodically? Sending it
> every time a probe fails could result in a large amount of notifications
> being sent into management consoles for example. Sending it just on the
> first failure isn't sufficient given the nature of notifications. What
> would you suggest?

I would suggest that a notification be sent if ALL of the ping retries
(as specified by pingProbeCount) FAIL.  The rationale is that if ANY of
the pings succeed, then we've established "connectivity" with the ping'ed
host (perhaps with degraded network performance).  Or conversely, if ALL 
of the pings FAIL, we've lost "connectivity" with the ping'ed host.

Regards,
--Alan

---

From: Harmen van der Linde <[email-masked]>
Date: Wed, 17 Feb 1999 12:45:02 -0500

Alan,

>of the pings FAIL, we've lost "connectivity" with the ping'ed host.

I'm not sure if I agree. Suppose I instruct the PING MIB to send 5 Ping
requests
and the last 2 Ping requests time out. This might indicate a significant
network 
connectivity failure. 

Whether or not it matters that 1 or a couple of more Ping requests get lost
depends on the known state of the network. When I have a congested network
I probably don't care much a few lost Ping requests. So, in this scenario,
your solution (i.e., send trap when all of the ping requests fail) might be
useful.

However, if I (think to) have a "clean" network one or more lost Ping requests
are probably interesting to consider. In this scenario your solution is
probably
not very useful.

My suggestion to solve this problem is:
- only send a Trap when one or more Ping requests time out
- add an object in the pingTable indicating whether a trap should be
  send in case one or more Ping requests time out (a bit similar to the 
  ciscoPingTrapOnCompletion object)

Harmen