Frye, R., Levi, D., Routhier, S., and B. Wijnen, "Coexistence between Version 1, Version 2, and Version 3 of the Internet-standard Network Management Framework", BCP 74, RFC 3584, DOI 10.17487/RFC3584, August 2003, <https://www.rfc-editor.org/info/rfc3584>.