I have invested some time in testing the behaviour of netmon and verified
by analyzing iptrace that netmon indead reacts to unsolicited traps telling
link up/down (generic trap ids 2 and 3):
As soon as netmon receives a link up or link down trap from trapd, sent by
an agent, netmon immediately pings the interface which has been told to be
up or down. Netmon does not wait until the end of the polling interval.
But netmon does not seem to react to any other trap in the same manner.
Sylvia Koch
The test was made with NetView for AIX 5.1.1, AIX 4.2.1 and an AIX based
Workstation with SNMP agent.
Leslie Clark <lclark@US.IBM.COM>@UCSBVM.UCSB.EDU> am 06.08.99 23:06:47
Bitte antworten an Discussion of IBM NetView and POLYCENTER Manager on
NetView <NV-L@UCSBVM.UCSB.EDU>
Gesendet von: Discussion of IBM NetView and POLYCENTER Manager on NetView
<NV-L@UCSBVM.UCSB.EDU>
An: NV-L@UCSBVM.UCSB.EDU
Kopie:
Thema: Re: Antwort: Interface down events
Has anyone thought any more about this? It seems like a really
interesting idea. However, it was my understanding that netmon
reacted not to incoming, unsolicited traps in this manner, but to
its own discovery of a down interface. That is, if it finds one down,
it checks the rest immediately rather than waiting until their scheduled
time, so as to make sure all interfaces were in sync.
My point is, I don't think it's just 6/2 traps it does not react to, it is
anyone's unsolicited generic traps as well. I think it only reacts
to traps it generates itself. I could be wrong. It would be nice to know.
The original question here was how Netview could be so responsive
on a 5 minute polling interval that it appears to respond in realtime
to an outage. I suggest that it is all luck and not magic. In my experience
it sometimes takes the full 5 minutes. It all depends on where netmon
is in its polling cycle. Yes, Kashif, the ping frequency IS the polling
frequency that you set in the SNMP configuration dialog.
Cordially,
Leslie A. Clark
IBM Global Services - Systems Mgmt & Networking
(248) 552-4968 Voicemail, Fax, Pager
---------------------- Forwarded by Leslie Clark/Southfield/IBM on 08/06/99
04:48 PM ---------------------------
"Prokott, Joe" <Joe.Prokott@WESTGROUP.COM> on 08/02/99 09:52:33 AM
Please respond to Discussion of IBM NetView and POLYCENTER Manager on
NetView
<NV-L@UCSBVM.UCSB.EDU>
To: NV-L@UCSBVM.UCSB.EDU
cc:
Subject: Re: Antwort: Interface down events
How does netmon indentify a "link down" and "link up" trap??? We have
Cisco
"Link down" and "Link up" traps that are enterprise(generic ID=6) specific,
can netmon distinguish these as valid "link down" and "link up" traps??? I
don't think so, as we don't see the extra netmon polling getting done as is
suggested in the netmon man page. I'm wondering if netmon for these "link
down" and "link up" traps just considers traps where the generic ID=2 (link
down) and generic ID=3 (link up)? If netmon in fact does look at these
link
down/up traps and does do the polling that is indicated in the man page, it
would be nice if we(all Netview users) could configure enterprise specific
link down/up traps that could be added into this auto. polling process that
netmon already does have coded, but only for some specific generic ID link
down/up traps.
Joe Prokott - West Group
Network Architect
610 Opperman Drive
St. Paul, MN 55123
Phone: 651-687-4536
Fax: 651-687-6946
E-mail: joe.prokott@westgroup.com
-----Original Message-----
From: Sylvia Koch [mailto:sylvia.koch@EMPRISE.DE]
Sent: Friday, July 30, 1999 4:32 PM
To: NV-L@UCSBVM.UCSB.EDU
Subject: Antwort: Interface down events
In the manpage to netmon you can find the following explanation to your
observation:
If netmon receives a link down or link up trap from the trapd daemon,
netmon will immediately ping the interface card identified with that link.
Then it will ping every interface card in that device. You will notice
extra network traffic, therefore, when links are going up and down.
Hope this helps
Sylvia Koch
Kashif Karim <kashif_karim@YAHOO.COM>@UCSBVM.UCSB.EDU> am 30.07.99 18:30:24
Bitte antworten an Discussion of IBM NetView and POLYCENTER Manager on
NetView <NV-L@UCSBVM.UCSB.EDU>
Gesendet von: Discussion of IBM NetView and POLYCENTER Manager on NetView
<NV-L@UCSBVM.UCSB.EDU>
An: NV-L@UCSBVM.UCSB.EDU
Kopie:
Thema: Interface down events
How much is the intervals set for Netview polls (pings) for Interface
status on Network Devices. It has to be different from the Status
Polling parameter on SNMP Config. because its 5m on my network but on
the other hand, OV Interface down events seem to be generated in real
time.
Kashif
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