I'll try to evaluate the NetFlow of opFlow with Cisco ASA, since Opmantek opFlow was installed in this entry.
opFlow：NetFlow Analyzer and Collector
opFlow CANNOT collect ASA FlowRecord
The trouble occurs after starting test of opFlow.
None is displayed although Flow Record is sent...
There are no problems with checking NetFlow packets by tcpdump, NMIS opFlow settings are certain...
NetFlow of Cisco ASA is difference from NetFlow v9
I found the document that NetFlow of ASA is difference from originally NetFlow Version 9.
NSEL：NetFlow Secure Event Logging
It is made from NetFlow v9 but it seems to have stateful mechanism.
I think the difference is came from that ASA is Firewall.
Support Discussion in Opmantek Community
There are discussions of this in Opmantek Community.
Unfortunately, now opFlow does NOT support NSEL (ASA's NetFlow)...
I'm going to generate FlowRecord with Cisco CSR1000V.