I am not sure if this is the "official fix" or not, but if you run netmon
with the "-u" flag (unnumbered interface support), then the loopback
interfaces should be discovered. I experienced the same problem while beta
testing 6.0, and stumbled across this solution by accident.
Joel Gerber - I/T Networking Professional - USAA Information Technology Co.
- San Antonio, TX
* (210)913-4231 * mailto:Joel.Gerber@USAA.com "
http://www.usaa.com
-----Original Message-----
From: Kuffer Andreas [SMTP:Andreas.Kuffer@kuoni.ch]
Sent: Friday, July 07, 2000 10:08
To: 'IBM NetView Discussion'
Subject: RE: [NV-L] What happened to netmon Flag?
Regarding to the loopback masks I absolutely agree with you. But...something
must have changed from 5.1.2 to 6.0 in the way netmon discovers loopback
interfaces since the "old" netview had no problems with them.
While trying around I finally discovered the device correctly (put the
loopback address into the seedfile) and after 2 or 3 trys it finally got
discovered. If as an alternative put a Lan-ip-address in the seedfile the
device gets discovered without the loopback interface. Even better, there is
no "loopback" object at all in the database.
Leslie pointed out that it could be related to the location.conf file and
entries in the nettl.log. Next week I'll do more investigation on that topic
With kind regards / mit freundlichen Gruessen
Andreas Kuffer (System Manager UNIX and Enterprise Management)
-----Original Message-----
From: Sean Davidson [mailto:sean.davidson@mail.publix.com]
Sent: Freitag, Juli 07, 2000 16:38
To: 'IBM NetView Discussion'
Subject: RE: [NV-L] What happened to netmon Flag?
The loopback interface on a Cisco router and the loopback interface
on a standard TCP/IP machine (127.0.0.1) are two different things. The
loopback on a standard TCP/IP machine is typically used for communication
between processes on that machine. So a 255.255.255.255 mask is valid.
The loopback interface on a Cisco router is a software interface
that only drops when it is either intentionally shutdown or the router loses
power. Other than that, it is a just like any other interface on the router.
You have to give it a valid IP address with a valid subnet mask.
255.255.255.255 (network of all 1's) is never a valid TCP/IP subnet mask.
There are no bits left over for hosts. The loopback interface on the cisco
router is typically used to tie Cisco processes like
DLSW,RSRB,BSTUN,STUN,etc...
If you have a primary and backup link on a router and you tie any of
those processes to a real physical interface, that process no longer
functions when the primary interface goes down and the backup link recovers
the connectivity. This is where the Cisco loopback interface is useful. It
is always up.
I don't believe the -L netmon flag you mention is the problem. Check
the MIB2 interface table reported by the router and see if the loopback
interface is there.
__________________________
Thanks,
Sean Davidson
Sr. Network Systems Engineer
Publix Super Markets, Inc.
P.O. Box 32015
Lakeland, Fl. 33802-2015
Email - sean.davidson@publix.com
Voice - (863) 686-8754 x6889
Fax - (863)616-5895
-----Original Message-----
From: Kuffer Andreas [mailto:Andreas.Kuffer@kuoni.ch]
Sent: Friday, July 07, 2000 3:48 AM
To: 'IBM NetView Discussion'
Subject: RE: [NV-L] What happened to netmon Flag?
I checked the netmask of the loopback interface, it was
indeed set to 255.255.255.252. I asked the network guys why and the answer
was that in earlier times you were not allowed (unable) to set a mask of
255.255.255.255. So the "loopback-netmask"-design of our network is
255.255.255.252 due to historical reasons.
Anyway we reconfigured the Cisco 1600 to 255.255.255.255,
did a demand poll and also a new discovery but received the same results as
I posted before.
I will call support today but I'm still interested if there
is anybody out there with NetView 6.0 discovering loopback interfaces.
With kind regards / mit freundlichen Gruessen
Andreas Kuffer (System Manager UNIX and Enterprise
Management)
-----Original Message-----
From: lclark@us.ibm.com [ <mailto:lclark@us.ibm.com>]
Sent: Donnerstag, Juli 06, 2000 16:30
To: IBM NetView Discussion
Subject: Re: [NV-L] What happened to netmon Flag?
The -L flag was dropped in V6 (made a no-op) because it was
no longer
needed. This is because, according to the internal update I
attended,
32-bit masks are now fully supported; 32-bit masks are
generally used for
software loopback interfaces. The connection is not exactly
clear to me,
but I have seen loopbacks discovered successfully in V6,
whether the
loopback was the address specified in the seedfile or not.
So by my
voodoo-problem-determination methodology, I would suggest
checking
the mask on the loopback that is missing. If it is not
255.255.255.255,
make
it so. If it is already so, look for some other, more
mundane discovery
problem, or call Support with a trace of the discovery
handy.
Cordially,
Leslie A. Clark
IBM Global Services - Systems Mgmt & Networking
Detroit
Kuffer Andreas <Andreas.Kuffer@kuoni.ch>@tkg.com on
07/06/2000 04:59:40 AM
Please respond to IBM NetView Discussion <nv-l@tkg.com>
Sent by: owner-nv-l@tkg.com
To: "'IBM NetView Discussion'" <nv-l@tkg.com>
cc:
Subject: [NV-L] What happened to netmon Flag?
AIX 4.3.2, NV 5.1.2 and NV 6.0
in version 6.0 of netview it seems that one flag of netmon
(-L, discover
loopback interfaces with other address than 127.0.0.0) was
withdrawn.
I have a Cisco 1600 with loopback interface 10.10.224.85
and three other
interfaces
Demand poll with NV 5.1.2 (netmon runs with -L):
Interface 10.10.232.86 (currently up) responded to ping
Interface 10.10.21.1 (currently up) responded to ping
Interface 10.10.224.85 (currently up) responded to ping
Interface 10.10.240.86 (down since 07/03/00) ping timed
out
Demand poll with NV 6.0 shows:
Interface 10.10.232.86 (currently up) responded to ping
Interface 10.10.21.1 (currently up) responded to ping
Interface 10.10.240.86 (down since 07/03/00) ping timed
out
So it looks like netmon V6.0 doesn't discover the loopback
interface I'd
like to see. Does that work as designed? Did I miss
anything? Can I use an
undocumented "-L feature"?
Any help is very welcome...Andreas
With kind regards / mit freundlichen Gruessen
Andreas Kuffer (System Manager UNIX and Enterprise
Management)
Kuoni Travel Ltd.
Dep. TOU
Neue Hard 7
CH-8010 Zuerich
Switzerland
Telefon : + 41 1 277 52 41
Fax : + 41 1 272 52 55
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