SNMP MIB files of Advantech routers
In category Routers .
You can find SNMP related information in the "SNMP Object Identifiers" application note:
https://icr.advantech.com/download/application-notes#snmp-object-identifiers
A direct link to the MIB files:
https://bitbucket.org/bbsmartworx/snmp-mib/src/master/routers/