The arp cache will only store the mac
address of the local router that is forwarding packets on behalf of the IP
address you are interested. The real mac address is not present in the arp
table on the router (unless by coincidence, the router has another interface
into the subnet where the device actually resides). I believe the same would be
true for the netview box’s arp cache – it’s going to reflect
the mac address of the device local to the NetView server (such as the local
router) that can reach the end device IP address.
Short answer: I don’t think arp
cache has anything to do with it. I could be wrong.
From:
owner-nv-l@lists.us.ibm.com [mailto:owner-nv-l@lists.us.ibm.com] On Behalf Of Freeman, Michael
Sent: Thursday, October 07, 2004
12:25 PM
To: nv-l@lists.us.ibm.com
Subject: [nv-l] how does netmon
interact with the ARP cache?
I have noticed that if a device goes down, and then comes
back up before netmon “magically notices it”, if you ping the
device, the object status will change in NetView. I assume this is because
NetView is somehow monitoring the arp tables? We are using NetView 7.1.3 on
Solaris and I am kind of curious to know how netmon and the arp cache works. It
seemed like in my tests with my network simulator, If I took down 200 nodes,
and then brought them up before netmon’s polling cycle kicked in, that if
I pinged every one of them (with a script of course), about only 10 or so nodes
would immediately have their object status changed in NetView. How does netmon
divvy up the workload? Helper threads? Timeslicing ?
*** Note new e-mail address
--
Michael J. Freeman
Netco Government Services
mfreeman@netcogov.com
--