RE: Netview discovery process

[James_Shanks@tivoli.com]

This overview is essentially  correct but it doesn't address some very essential
additions and modifications which have been made, such as seed file processing,
and how it is different on NT than on UNIX,   how ping  spray and speed
discovery work, how netmon deals with HSRP, unnumbered interfaces,  and so on.
That is why Leslie suggested that the original questioner tell us what problem
he is trying to solve.  It is difficult to answer anyone when they take a huge
subject and demand to know everything in great detail.  Since we have no single
published document  to refer to him, I suspect that no one felt like undertaking
to write one.    Much of this information can be gleaned, however, from the
published doc - see Installation and Configuration and the Admin Guide on using
a seed file, and the release notes on HSRP, and the netmon man pages for a lot
of it.


James Shanks
Tivoli (NetView for UNIX and NT) L3 Support


"Niclas Nilsson" <niclas@carica.com> on 05/22/2000 05:30:45 PM

Please respond to IBM NetView Discussion <nv-l@tkg.com>

To:   "IBM NetView Discussion" <nv-l@tkg.com>
cc:    (bcc: James Shanks/Tivoli Systems)
Subject:  RE: [NV-L] Netview discovery process




RE: [NV-L] Netview discovery processSince NetView is initially developed
with HP OpenView NNM as a base, I can tell you how OpenView works. I guess
this has not been changed in NetView.

The discovery process is handled by the netmon deamon. When the discovery
process starts, the netmon deamon starts by contacting the NetView server's
own SNMP agent. Using SNMP get it will retrive the arp cache. The arp cache
contain a lot of ipadresses to continue to search.

Each node in the collected arp cache is then pinged and if there is a
connection the netmon deamon issues a number of SNMP get commands to collect
information about SysObjectID etc. from the node (approximately the same
information as is received when performing a demand poll).
If the node does not support SNMP or if you have a wrong get community name
set you will not be able to get any of the SNMP information (you will get an
empty square for the node on the desktop).
One of collected MIB variables form the node is the arp cache => new
ipadress to continue the search.

In addition to collecting the first arp cache from the NetView server, nemon
will also contact the default gateway to collect the arp cache information.

The serach will then continue like this, collecting more and more arp
caches, ping the nodes and do a number of SNMP gets.

If you have to few nodes in the environment supporting SNMP or if you have
the wrong SNMP get community name set the discovery process will be very
slow. Please note thai if you by mistake change the SNMP community name of
the SNMP agent at the Netview server (without informing the NetView server)
the netmon deamon will not be able to start at all.

In addition to collecting arp cahces you can also configure netmon to
collect routing tables, eg for WAN routes, but this is not the default
behaviour.

 I hope this helps,

regards
Niclas


  -----Original Message-----
  From: owner-nv-l@tkg.com [mailto:owner-nv-l@tkg.com]On Behalf Of MERY
Olivier (Neuilly Gestion)
  Sent: Monday, May 22, 2000 8:35 AM
  To: 'IBM NetView Discussion'
  Subject: RE: [NV-L] Netview discovery process


  If you have time, you can analyze the traffic generated by the netview
server.
  It will give you a good idea of the information gathered from devices.

  Regards,

  Olivier MERY
  CETELEM
  20, avenue Georges Pompidou
  92595 LEVALLOIS-PERRET Cedex - FRANCE




  -----Original Message-----
  From: lclark@us.ibm.com [mailto:lclark@us.ibm.com]
  Sent: Saturday, May 20, 2000 10:35 PM
  To: NV-L@tkg.com
  Subject: Re: [NV-L] Netview discovery process





  Reggie, I suspect that the information you seek would be considered
  intellectual capital by Tivoli. If you are having a specific problem, then
  people can usually help you with that, but otherwise, how the code
  works is, I am sure, proprietary.

  Cordially,

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

  ---------------------- Forwarded by Leslie Clark/Southfield/IBM on
  05/20/2000 04:32 PM ---------------------------

  "Rama, R. (Reggie)" <ReggieR@nedcor.co.za>@tkg.com on 05/18/2000 04:14:02
  AM

  Please respond to IBM NetView Discussion <nv-l@tkg.com>

  Sent by:  owner-nv-l@tkg.com



  To:   "'nv-l@tkg.com'" <nv-l@tkg.com>
  cc:
  Subject:  [NV-L] Netview discovery process






  Hello Netview Users

  I have searched the list for a detailed explaination of the Netview
  (netmon) discovery process but could not find anything detailed enough.
  Does anyone have any documentation w.r.t this process .i.e. how does the
  netmon daemon go about discovering a network. I require specific details
  such as : does/how it uses pings, snmpgets, looks at routing tables, arp
  caches, order of the discovery process etc.

  Thanks in advance for all assistance.

  Regards
  Reggie Rama
  ESM - Technology & Operations Division
  Nedcor Bank Limited (South Africa)

  Tel : +27 - 011 - 8813989
  Fax : +27 - 011 -  8814113
  e-mail : reggier@nedcor.co.za






  _________________________________________________________________________

  NV-L List information (unsubscribing, policies, posting, digest version,
  searchable archives): http://www.tkg.com/nv-l

Since NetView is initially developed with HP OpenView NNM as a base, I can tell you how OpenView works. I guess this has not been changed in NetView.

 

The discovery process is handled by the netmon deamon. When the discovery process starts, the netmon deamon starts by contacting the NetView server's own SNMP agent. Using SNMP get it will retrive the arp cache. The arp cache contain a lot of ipadresses to continue to search.

 

Each node in the collected arp cache is then pinged and if there is a connection the netmon deamon issues a number of SNMP get commands to collect information about SysObjectID etc. from the node (approximately the same information as is received when performing a demand poll).

If the node does not support SNMP or if you have a wrong get community name set you will not be able to get any of the SNMP information (you will get an empty square for the node on the desktop).

One of collected MIB variables form the node is the arp cache => new ipadress to continue the search.

 

In addition to collecting the first arp cache from the NetView server, nemon will also contact the default gateway to collect the arp cache information.

 

The serach will then continue like this, collecting more and more arp caches, ping the nodes and do a number of SNMP gets.

 

If you have to few nodes in the environment supporting SNMP or if you have the wrong SNMP get community name set the discovery process will be very slow. Please note thai if you by mistake change the SNMP community name of the SNMP agent at the Netview server (without informing the NetView server) the netmon deamon will not be able to start at all.

 

In addition to collecting arp cahces you can also configure netmon to collect routing tables, eg for WAN routes, but this is not the default behaviour.

 

 I hope this helps,

 

regards

Niclas

 

 

-----Original Message-----
From: owner-nv-l@tkg.com [mailto:owner-nv-l@tkg.com]On Behalf Of MERY Olivier (Neuilly Gestion)
Sent: Monday, May 22, 2000 8:35 AM
To: 'IBM NetView Discussion'
Subject: RE: [NV-L] Netview discovery process

If you have time, you can analyze the traffic generated by the netview server.
It will give you a good idea of the information gathered from devices.

Regards,

Olivier MERY
CETELEM
20, avenue Georges Pompidou
92595 LEVALLOIS-PERRET Cedex - FRANCE

-----Original Message-----
From: lclark@us.ibm.com [mailto:lclark@us.ibm.com]
Sent: Saturday, May 20, 2000 10:35 PM
To: NV-L@tkg.com
Subject: Re: [NV-L] Netview discovery process

Reggie, I suspect that the information you seek would be considered
intellectual capital by Tivoli. If you are having a specific problem, then
people can usually help you with that, but otherwise, how the code
works is, I am sure, proprietary.

Cordially,

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

---------------------- Forwarded by Leslie Clark/Southfield/IBM on
05/20/2000 04:32 PM ---------------------------

"Rama, R. (Reggie)" <ReggieR@nedcor.co.za>@tkg.com on 05/18/2000 04:14:02
AM

Please respond to IBM NetView Discussion <nv-l@tkg.com>

Sent by:  owner-nv-l@tkg.com

To:   "'nv-l@tkg.com'" <nv-l@tkg.com>
cc:
Subject:  [NV-L] Netview discovery process

Hello Netview Users

I have searched the list for a detailed explaination of the Netview
(netmon) discovery process but could not find anything detailed enough.
Does anyone have any documentation w.r.t this process .i.e. how does the
netmon daemon go about discovering a network. I require specific details
such as : does/how it uses pings, snmpgets, looks at routing tables, arp
caches, order of the discovery process etc.

Thanks in advance for all assistance.

Regards
Reggie Rama
ESM - Technology & Operations Division
Nedcor Bank Limited (South Africa)

Tel : +27 - 011 - 8813989
Fax : +27 - 011 -  8814113
e-mail : reggier@nedcor.co.za

_________________________________________________________________________

NV-L List information (unsubscribing, policies, posting, digest version,
searchable archives): http://www.tkg.com/nv-l