Here’s some useful ‘built-in’ Wireshark capability, for troubleshooting on the supervisor. The feature only works with process switched traffic.

nexus#ethanalyzer local interface inband capture-filter  “udp port 161”

nexus#ethanalyzer local interface inband capture-filter  “udp port 161” detail

nexus#ethanalyzer local interface inband capture-filter “udp port 161” write bootflash:snmp.pcap

An ACL log is necessary to capture data plane traffic.  Steps for this can be found here: Ethanalyzer Link

http://www.cisco.com/c/en/us/support/docs/switches/nexus-7000-series-switches/116136-trouble-ethanalyzer-nexus7000-00.html