MIB's version, the current version is 2. 1 - original version. 2 - field rlRadiusServerUsage was added to rlRadiusServerEntry
Sources for this description
Multiple manufacturers; see the original MIB MIB copies (LibreNMS/Observium Community)Dell MIB copies (LibreNMS/Observium Community)Netdisco MIB archive copiesNETGEAR official product and EOL MIB downloads