nv-l

Re: ping response

1999-08-26 10:09:40
Subject: Re: ping response
From: Leslie Clark <lclark AT US.IBM DOT COM>
To: nv-l AT lists.tivoli DOT com
Date: Thu, 26 Aug 1999 10:09:40 -0400
Well, yes, I hear it too. Somebody out there must know the answer. This
customer as lots and lots of 3Com Superstacks, and if I take netmon down
for a while and bring it back up, about one third of those devices are
unpingable for a half hour to an hour. Little by little they come back. And it
is not false alarms, no amount of pinging fixes it until some time has elapsed.
Maybe the same sort of thing you guys are seeing? It feels like the devices
don't know the way back to the server for a while, then they do.  Could it be
their configuration, routing tables, arp cache? Far different subnets in most
cases,
I think. Waiting for clues...

Cordially,

Leslie A. Clark
IBM Global Services - Systems Mgmt & Networking



In my case the device was on a different subnet. Now the puzzlement. Pings
originating from other devices on the same subnet as my NetView server
worked. The route tables of these other devices are the same as my NetView
server therefore the same routers were coming into play. Pings from my
NetView server to all other devices in this other subnet worked. It would
also eliminate the arp cache issue. Anyone besides me hear the theme song of
"The Twilight Zone"?

Blaine Owens
Eastman Chemical Company
Phone - (423)-229-3579
Fax - (423)-229-1188
bowens AT eastman DOT com

> -----Original Message-----
> From: Chris J. Garlick [SMTP:chris.garlick AT eu.effem DOT com]
> Sent: Wednesday, August 25, 1999 11:44 AM
> To:   NV-L AT UCSBVM.ucsb DOT edu
> Subject:      Re: ping response
>
> ....  is it possible that the web server and Netview box are on different
> IP
> segments..?  I have observed cases of messed up routers passing some
> sub-protocols (SNMP,  HTTP etc) but not others (eg ICMP (ping).....) ?
> The router may have been bounced/reset later, accounting for the
> mysterious
> 'fix' ...?
>
> Kind Regards
>
>
>
>
> Please respond to Discussion of IBM NetView and POLYCENTER Manager on
>       NetView <NV-L AT UCSBVM.ucsb DOT edu>
>
>
>
>  To:      NV-L AT UCSBVM.ucsb DOT edu
>
>  cc:
>
>  Subject: Re: ping response
>
>
>
>
>
>
>
> Just curious - AIX 4.3.2? We had a similar problem a while back. The
> problem
> just "went away" - I am still puzzled over it. We could not ping a certain
> web server from NetView but could ping the server from other hosts. Now to
> add to my confusion - all the while that pings were failing I could do
> SNMP
> gets and HTTP requests just fine - only pings were failing. I might add
> that
> two different ping programs were tried (the AIX supplied one and the
> public
> utility called "fping") - both failed. It was not an arp cache problem. As
> mysteriously as the problem appeared it just went away.
>
> Blaine Owens
> Eastman Chemical Company
> Phone - (423)-229-3579
> Fax - (423)-229-1188
> bowens AT eastman DOT com
>
> > -----Original Message-----
> > From: John Creasey [SMTP:creasey AT OZEMAIL.COM DOT AU]
> > Sent: Wednesday, August 25, 1999 9:01 AM
> > To:   NV-L AT UCSBVM.ucsb DOT edu
> > Subject:      Re: ping response
> >
> > Recently our network operators reported a very similar thing
> > happening.  They were certain an interface was up but netview
> > couldn't ping it.  I wasnt present so I was very much baffled
> > by their claims.
> >
> > Have you tried to reproduce the problem?  If it is reproducible
> > it could be a bonafide bug.
> >
> >
> > > -----Original Message-----
> > > From: Discussion of IBM NetView and POLYCENTER Manager on NetView
> > > [mailto:NV-L AT UCSBVM.UCSB DOT EDU]On Behalf Of Frantsen Christian
> > > Sent: Wednesday, 25 August 1999 19:26
> > > To: NV-L AT UCSBVM.UCSB DOT EDU
> > > Subject: ping response
> > >
> > >
> > > I noticed something strange the other day when trying some
> > > things in our
> > > lab.
> > >
> > > I unplugged a switch by removing the TP-cord and i got a node down in
> > > netview (obviously =))
> > > then I put the cord back in and I couldn't ping the switch
> > > from the netview
> > > map, there was no response,
> > > I got response from it if I pinged it from a machine right
> > > next to me, I
> > > tried again from netview, no response
> > > then I made a ping from the commandline on the
> > > netview-machine. Now i got a
> > > response and after that it worked from the map again.
> > >
> > > Anyone got some feedback on this?
> > >
> > > -----------------------------------------
> > > Christian Frantsen
> > > Technical Operations
> > >
> > > Internoc Scandinavia AB
> > > Tel: +46-36-194843
> > > Fax: +46-36-194651
> > > http://www.internoc.se
> > >


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