Hi all.
please not, that if you use L2 GRE Tunnel to transmit the mirrored traffic to purview and if your gre port is tg.2.24 you need to insert an 10GE optic. It will not work with an 1GE optic.
even if tg.2.24 is up and also the tunnel interface is up. no applications are detected and no fingerprints will match.
Save some time in troubleshooting, insert an 10GE optic and reset the tunnel interface. Then you will see some applications.