After compiling and adding a vendor mib into Spectrum MIB Tools, the mib is placed in the Unknown folder and not in the expected vendor folder. For example, the IB-SMI-MIB as seen below:
Release: Any version of Spectrum
During import of any mib in MIB Tools, Spectrum finds the common OID between the MODULE-IDENTITY and the Root Node of the mib. If the common OID has vendor, it places the MIB in the vendor folder.
The Root Node of the IB-SMI-MIB.mib is "enterprises" (126.96.36.199.4.1), children of the root node are "infoblox (188.8.131.52.4.1.7779), ibDNSServ ( 184.108.40.206.4.1.32) and ibDHCPServ (220.127.116.11.4.1.9999)". The common OID in between all children of the root node is 18.104.22.168.4.1. As vendor is empty in the common OID, Spectrum placed the IB-SMI-MIB.mib in "Unknown" folder.
As multiple vendors defined in the IB-SMI-MIB.mib, the common OID is "22.214.171.124.4.1"
126.96.36.199.4.1.7779 ( 7779 - infoblox )
188.8.131.52.4.1.32 ( 32 - Santa Cruz Operation )
184.108.40.206.4.1.9999 ( 9999 - Zerna, Koepper & Partner )