RE: [nv-l] Netmon on NT

["Barr, Scott" <Scott_Barr@csgsystems.com>]

Isn't the 20 coded as 10ths of a second = 2 seconds? 1000 milliseconds (1 second) would be a long ping time even in a serial 56K network.

 

20 seconds for a ping time out is an eternity. And remember with SNMP polling, failure on a first attempt will result in doubling the timeout value the second attempt and doubling the timeout again on a third try ad nauseum. I don't know if the ICMP timeout is doubled each retry with pinging but I know it is for SNMP

-----Original Message-----
From: owner-nv-l@lists.us.ibm.com [mailto:owner-nv-l@lists.us.ibm.com]On Behalf Of Gareth Holl
Sent: Wednesday, December 03, 2003 5:43 PM
To: nv-l@lists.us.ibm.com
Subject: Re: [nv-l] Netmon on NT

Timeouts depend on the device or more so the speed of the connection you would have been the device and NetView. I would consider 20 seconds to be too long a timeout for most ethernet devices. Generally speaking the default is satifactory - how long would you think it takes for a ping to make it to it's destination and back again - try it on the command line. Double it to be sage if you like, but 20 seconds would make for a slooooooow network. Of course if you are monitoring devices on the other end of a 64k serial (eg. dial-up) link, then maybe not.

Ping spray has nothing to do with community names. A ping spray is only used during discovery and is basically a series of ping tests of every valid IP address in a given subnet where it listens for responses as a means of learning of a devices existance. Usually netmon only pings IPs it has learnt about from the route tables (and other lists) from devices it has already discovered and has successfully SNMP polled. netmon can also learn of other devices via a seedfile, its own arp cache, or its own default route.

Gareth Holl
Staff Software Engineer
gholl@us.ibm.com

IBM Software Group - Tivoli Brand
Research Triangle Park,  North Carolina.

"Christopher J Petrina" <cjp8@meadwestvaco.com> Sent by: owner-nv-l@lists.us.ibm.com 12/03/2003 06:23 PM Please respond to nv-l

To:        nv-l@lists.us.ibm.com         cc:                 Subject:        Re: [nv-l] Netmon on NT

WOuld you consider 20 seconds for 1st timeout fairly long to keep them in there.  with snmp setup properly.  We are not using Ping Spray.   Is Ping Spray more practical when we are not exactly sure of all the community strings on all the devices?