I have been using NTA 3.8 without a problem for several months. I recently enabled IP Multicast routing and IP IGMP on my Procurve 5412zl. Since I have done this, I am unable to receive sflow data to the NTA now. I tried re-enabling sflow on the switch and made sure it was sending to the correct IP/Port. I could also ping the NTA server from the switch. I am also monitoring TRK1 via NPM.
sflow 1 destination IP of NTA/NPM 2055
sflow 1 polling Trk1 60
sflow 1 sampling Trk1 50
I just upgraded the NTA to 3.9 RC2 and now my sflow is working again.