nv-l

Re: [nv-l] Generating Topology Map with MLMs

2005-09-08 16:45:55
Subject: Re: [nv-l] Generating Topology Map with MLMs
From: Jane Curry <jane.curry AT skills-1st.co DOT uk>
To: nv-l AT lists.us.ibm DOT com
Date: Thu, 08 Sep 2005 21:45:07 +0100
Hi Usman,
If I understand you correctly, you want to manage several customers, each of whom has several different IP networks. In this scenario, MLM is not the right answer, in my personal opinion, as MLM will only do automatic discovery for the single network that the MLM is attached to. So, for each customer, you would need as many MLMs as your customer has networks.
If it is important to have a single NetView with a view of many
different networks across many different customers, you should go with
one NetView and you need to think about security considerations like
keeping customer data secure from other customers and, also, whether you
have multiple customers who may have the "same" network" eg. several
using the same subnets of network 10. If you have this latter scenario,
then look at the Comprehensive NAt (CNAT) package.
If you have firewalls between your central NetView and your customers
that prevent ping (which is fundamentally required for NetView automatic
discovery), then look at the loadhosts utility which allows you to
manually "discover" nodes programmatically and then, if SNMP is allowed
through firewalls, you can use the $ syntax in you seedfile to poll
these devices using SNMP. loadhosts gets you around the initial
discovery problem.
Cheers,
Jane

usman.taokeer AT s-iii DOT com wrote:

James i will cut this to short, what i want to achieve here is to
have a single topology MAP having showing subnet of different
customers. NOW i cant just give my NetView access to all these subnet(
these are not just subnet but complete enterprise networks). Now here
i will go with your recommendation that what should i do, use MLM or
install NetView in each of customers network?
I am not sure that NetView can share Topology map with other NetView
servers? and if yes, then how?
forwarding events is not a problem but i also want to have single
console of Topology map of all networks that are being managed!

Regards,
Usman Taokeer
Si3.


*James Shanks <jshanks AT us.ibm DOT com>*
Sent by: owner-nv-l AT lists.us.ibm DOT com

06-09-05 07:11 PM
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MLM is not a substitute for NetView but an adjunct to it.  Whether it is
suitable or not for the purpose you want, only you can decide.
MLM only discovers devices in one subnet; it's own.  That's why you would
need one for each subnet of the customer's network if you want to use MLM
discovery.  it is possible to manually add a few devices in another subnet
to an MLM for monitoring, but there is no way to get it to automatically
monitor or discover more than its own subnet.  It is not a tiny NetView.
It's original design purpose was to monitor remote locations connected to
the central NetView by slow WAN links which could not sustain the constant
ping or SNMP traffic that Netview monitoring requires.

MLM's communicate with NetView via SNMP sets and gets, and also traps. You
have to have both the read and write community names correct in
ovsnmp.conf. You can also configure the trapd destination table in the MLM
to threshold on outside traps.  Once netmon finds an MLM using an SNMP get
with the read community string, it send an SNMPset to that MLM telling it
to start reporting the discovery and monitoring data it has to the central
location.  The nodes the MLM has discovered will get added to NetView
topology provided that netmon can ping them to verify their authenticity.

Combining two distinct  customer networks under one NetView will only work
well if they have separate and distinct addressing schemes, since
duplicates are not allowed,  unless you also deploy CNAT gateways between
them to do translations.

You might profitably spend some time reading in the MLM doc before making
your deployment decision.  You might also deploy a test one and play with
it a little too.  That's easy enough to do.

James Shanks
Level 3 Support  for Tivoli NetView for UNIX and Windows
Tivoli Software / IBM Software Group


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