from the following document it looks like we only need to add ip flow command on the l3 interfaceThe ip multicast netflow output-counters enables the calculation of output bytes/packets for an ingress flow.http://www.cisco.com/en/US/docs/switches/la...
here is link which explains snmp config for 2960shttp://www.cisco.com/en/US/docs/switches/lan/catalyst2960/software/release/12.2_55_se/configuration/guide/swsnmp.html#wp1076836