Symptom

Traffic is dropped after getting the ISystemActivator Response from the MSRPC server with a Format Error message, if inspection is disabled and Pass used as action for MSRPC traffic the issue disappears.

Conditions

ISR4451 running 16.09.05 ZBF enabled with inspact action for MSRPC traffic DMVPN configure

Workaround

1.- Bypass msrpc inspection: parameter-map type inspect pmap no application-inspect msrpc class-map type inspect match-all cm-msrpc match protocol msrpc policy-map type inspect pm-bypass-msrpc-inspect class cm-msrpc inspect pmap class default drop

Further Problem Description