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