title: ASN.1 definitions for basic SNMP exchanges
body: <p>What online resource is the authority for the complete set of ASN.1 definitions for the SNMP data structures used to request and respond with information? I am interested in versions 2c and version 3.</p>
  <p>In <a href="https://www.rfc-editor.org/rfc/rfc3416#section-3" rel="nofollow noreferrer">RFC 3416 Section 3</a>, I have found most of the definitions needed to use version 2c. However, the document has no mention of something that I have found on other resources referred to as the &quot;snmpv2 message&quot;. For example, this shows up in the <a href="http://wiki.treck.com/SNMP_Programmer%27s_Reference#SNMPv2c_Messages_and_PDU_Formats" rel="nofollow noreferrer">SNMP Programmers Reference Wiki</a> and in the blog post <a href="http://www.rane.com/note161.html" rel="nofollow noreferrer">Simple? Network Management Protocol</a>. It's the data structure that contains the community string, so it's role is essential, but I cannot find where the authoritative source (probably an RFC) with an ASN.1 definition.</p>
  <p>Similarly, I cannot find any authoritative ASN.1 definitions of SNMPv3 data structures. I found an <a href="https://github.com/tysonite/asn1-compiler/blob/dbb95123435c5e6c7174ee0232ee1836114f89a4/runtime/tests/snmpv3-example/snmpv3.asn" rel="nofollow noreferrer">ASN file in a github repo's test suite</a>, but I cannot find where this information was taken from.</p>
  <p>I would appreciate any help locating these. I'm usually a pretty good Googler, but my usual strategies are not turning anything up beyond what I've already linked to.</p>