Because MIB definitions are written by different people, there is no rule as to how roots are handled. Some MIB definitions define absolute module root, some define relative module root, some MIB definitions don't, while others use an IMPORT directive to reference another MIB definition that would contain root definitions.
ScanEngine Explorer provides simple methods to define roots. The only trick is understanding what they are. Once you understand roots you should have no difficulty resolving unknown root definitions for any module you wish to load MIB definitions.
Every MIB in a MIB definition is defined with a complete numeric OID, or a relative numeric OID from a defined parent. In order to resolve the relative OID we must have the OID for parent.
For example, the ieee802dot11 module is typically defined as OID 1.2.840.10036. But elsewhere you might see a MIB for this same module defined as an OID relative to a parent, i.e. US.10036, where US is defined as MEMBER-BODY.840, MEMBER-BODY is defined as ISO.2, and ISO is defined as 1. It is often the case that a MIB is defined relative to a parent, but the parent definition is not included, or defined by an IMPORTS reference to a parent module MIB definition.
The final arbitor is whether ScanEngine Explorer has all reference roots defined. If not, loading MIBs will halt on encountering any unknown root, and the specifics written to program log.
Methods to define roots
ScanEngine Explorer provides both tree view and alphabetical panels for all loaded MIBs.