Thanks for coming back ,

So it’s accepted to work with Siemens platform because as we discussed before facing unknown protocol drops on interfaces where Siemens PLC devices are connected using PROFINET.Gabor raised a bug CSCvi10141<   https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvi10141/?reffering_site=dumpcr>;;; and issue has been classified as cosmetic.
Unknown protocol drops reports the packets with unknown or un-configured protocol on a per interface basis. Therefore it can be any protocol that the router doesn't recognize. Siemens PLCs sometimes use non-standard Ethernet for communication.  For instance Profinet IRT packets are standard Ethernet .

Also , we are not able to force the SW to not filter the traffic unless using an ACL to filter the traffic and disabling the STP not recommend from cisco TAC it’s will cause a Network down situation  .

Please let me know if any assistance still needed from our side and how we can proceed with the case

Товарищи из Индии не совсем правы. У прфинет рт есть минимум 2 особенности: особое значение поля ethertype (что уже может быть поводом для некоторых коммутаторов отбросить пакет) и особая интерпретация vlan tag - что точно приведет к неадекватной реакции коммутатора, если он в этом поле будет искать именно vlan id