ModSnmp Manual v3.07 - 8. Constant OID Settings
The Constant OIDs pages enable you to map specific SNMP OIDs to constant values. This is particularly useful for providing identification information to SNMP managers, but may have other uses. A typical use would to provide values for sysName (OID 18.104.22.168.22.214.171.124) and sysContact (OID 126.96.36.199.188.8.131.52) - see RFC 3418.
The Constant OIDs are not included in the generated MIB file, since they are assumed to be already defined in other MIBs (e.g. sysName is defined in the standard SNMPv2-MIB file).
Details of all the constant-valued OIDs that you have added are displayed in the Constant OIDs page. See Section 8.1, “Defining Constant OIDs” for explanations of the values displayed in each column.