Hello, first of all sorry for my english it`s not pretty good but I hope you understand.

I want to monitor the multicast traffic (not the whole traffic) from the Cisco 3750 router and now I have been searching for the solution for a very long time. I try to get traffic information with SNMP. So I was looking for the correct OID and found the ipMRouteInterfaceHCOutMcastOctets-OID .1.3.6.1.2.1.83.1.1.4.1.8 to get the number of octets of multicast packets that have been sent on the interface. In my opinion it sounds very good.

So I asked for this value for interface 10302 with the following command:

snmpget -v 2c -c <community> <router> .1.3.6.1.2.1.83.1.1.4.1.8.10302

And the result was:

SNMPv2-SMI::mib-2.83.1.1.4.1.8.10302 = Counter64: 1484356

My problem is that the value is changing rarely. Here an extract from the log-file after executing the above command second by second (HH:MM:SS AM <octetvalue for Interface 10302>):

10:11:14 AM 140328

10:11:15 AM 159804

10:11:16 AM 159804

10:11:17 AM 173276

10:11:18 AM 173276

10:11:19 AM 173276

10:11:20 AM 173276

10:11:21 AM 173276

10:11:22 AM 178520

10:11:23 AM 178520

10:11:24 AM 184772

10:11:25 AM 187692

10:11:26 AM 196128

10:11:27 AM 196128

10:11:28 AM 196128

10:11:29 AM 209192

10:11:31 AM 209192

10:11:32 AM 209192

10:11:33 AM 209192

10:11:34 AM 209192

10:11:35 AM 209192

10:11:36 AM 209192

10:11:37 AM 209192

10:11:38 AM 209192

10:11:39 AM 209192

10:11:40 AM 209192

10:11:41 AM 209192

10:11:42 AM 209192

...

I don`t know why but the value is changing very differently (one second 140328, two seconds 159804, five seconds 173276, two seconds 184772,...)

I only need the multicast traffic for each interface, but I do not know where my mistake is. Is my OID the wrong one or is there another way to achieve my target? I am grateful for any help!

Markus