RE: [nv-l] seed file

[Stephen Hochstetler <shochste@us.ibm.com>]

NetView documentation gives the advice to put a caching name server on your Netview Server.   I would take that a step further and 'fix' troublesome nameserver configurations.  

1.  Run named on your NetView server

2.  Using an external process, discover your network and bring in the names

3. Using a script, process the NetView topology database and generate your own DNS zone files.  Put in the SNMP address of the device into the name lookup table.  Put ALL the interfaces into the reverse lookup files so that they map to the device name NetView is using.   

4.  Update your resolv.conf to use your local DNS first, then network DNS second.   This will give you good solid NetView DNS support with very little CPU costs.  New devices coming in will get their name from the network DNS.   Their name will be configured into the local DNS the next time you run your script to process the NetView database.

This drastically reduces CPU loads from large host files.   The nice thing is that once you have your script written, it is very close to painless for maintaining the names.

Monday, March 08, 2004 3:08 PM
To: nv-l@lists.us.ibm.com
cc: nv-l@lists.us.ibm.com, owner-nv-l@lists.us.ibm.com
From: "Christopher J Petrina" <cjp8@meadwestvaco.com>
Subject: RE: [nv-l] seed file

OUr issue with names is 
that we have a central database that has all the delvices within the network in 
it (Lotus Notes DB).   Not all these devices are in DNS.  They have 
added names for every interface on every device into this Lotus Notes DB in no 
particular fashion for denoting which interfaces belong to which device. 
 The naming scheme is not exactly consistent.  Because this is a large 
database of all the devices it is what I haev to work with. and we also have the 
same issues as others about HSRP ISDN backups and all that.   My main 
question was in how netview deals with the multiple entries of names for the 
same device.   Thank you for all the input.

Francois Le Hir <flehir@ca.ibm.com> Sent by: owner-nv-l@lists.us.ibm.com 03/08/2004 03:51 PM Please respond to nv-l

To:        nv-l@lists.us.ibm.com         cc:                 Subject:        RE: [nv-l] seed file

I tried the host file but it gave me more trouble than 
anything else as the
name resolution is a lot heavier on the CPU if the host 
file is big. The
main reason is that the Netview server was also a syslog 
server and syslogd
not being multithreaded, it started eating 100% of one cpu 
and dropping
traffic. Maybe if you don't have other name resolution intensive 
process it
would work but it all depends on the size of the host 
file.

Also I wonder what others do for the name resolution of HSRP 
interface ?
The way I do is to resolve the ip to the name of the primary 
router but it
lead to frequent problems when somehow Netview elect an HSRP 
interface to
be the "SNMP address" for a device.

Salutations, / 
Regards,

Francois Le Hir
Network Projects & Consulting 
Services
IBM Global Services
Phone: (514) 205 6695


  
                      
                      
                      
      
            "Evans, Bill" 
                      
                      
    
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            03/08/2004 03:21     
     RE: [nv-l] seed file           
     
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Another important item is to use only one name in DNS 
for each router.  All
the interfaces on that device should resolve to 
the same name.  The name
should resolve to the loopback address for the 
router.


This gives you the best functioning of NetView although there 
is a
continuing argument from many who want a unique DNS name for each 
interface
for other reasons.  I find the device name qualified by the 
interface name
(e.g. Router.Serial1/0) gives the uniqueness I need for 
interfaces. When
necessary I override the DNS with a local hosts file to 
achieve this.  In
my present situation the DNS has only the loopback 
address and I use hosts
to resolve the other names.


Bill 
Evans


-----Original Message-----
From: Paul 
[mailto:pstroud@bellsouth.net]
Sent: Monday, March 08, 2004 2:05 PM
To: 
nv-l@lists.us.ibm.com
Subject: Re: [nv-l] seed file


Chris,
Only 
use one IP for each device, you are causing netmon to do a lot of
additional 
and unecessary cycles. Let me explain:


netmon reads the entries from 
the seedfile, pings the node, if it
responds, it is added to the database and 
an SNMP poll in scheduled.
When the device is polled via SNMP all the 
interfaces are discovered
and finally the full device is added to the 
map.


If you put multiple IPs in the seedfile for the same device it 
will be
added and polled mutliple times, one for each ip in the seedfile. 
This
is uneccesary as netmon will already discover it via SNMP. That 
and
you might confuse things. Ie. netmon discovers on interface and adds 
it 
and finds another interface and 
adds it before the first SNMP poll
is completed. Now it must delete one of 
the devices(as we know they
are on the same device) and fixup the correct 
device. This is all
uneccesary processing.


The best practice is to 
add a single interface from each 
device.


Paul






Christopher J Petrina 
wrote:


>
> Greetings all,
>
> UNIX netview. 
 Using a seefile forl imited discovery.  In the seedfile
> I 
have multiple entries (multiple IP's) for the same device, ie(every
> ip 
interface of a single router) is in the seedfile.  When netview
> 
runs through the seedfile it finds the first IP of a device when it
> 
comes to the second IP of that device what does netview do.  Each 
IP
> interface also has an entryo in DNS as well.  Does netview 
change the
> name of the device if it finds another name.  Also once 
it has
> initially found it, and then polls the device (SNMP) what name 
will it
> chose for the device in netview, and why does it sometimes 
change the
> name of the device.
>
>
> Chris 
Petrina







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