SNMPSniffer 1.0 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. This free Mac app was originally produced by Calaveras Technologies Inc. The software belongs to Internet & Network Tools.
From the developer:
SNMPSniffer is a tool with a graphical interface to sniff SNMP packets over the network. The results might be saved into a file. SNMP commands can be optionally run from the interface.
You may want to check out more software for Mac, such as IPNetShareX, PPPoE Connector or tn3270, which might be similar to SNMPSniffer.