I am using transparent proxy and have noticed that the counts in the new N7 dpi module screen are always at zero. At first I wondered if I had ndpi configured properly, but I suspect this is normal behavior when using transparent, i.e., the ndpi module never inspects the packets because they are routed to the proxy server/content filter.
The firewall documentation confirms that this is probably true:
“nDPI rules can’t block the http/https traffic if web proxy is enabled in transparent mode.”
It’s a shame to not at least be able to use ndpi to monitor what kind of traffic, which sites, are being most heavily used, but if that’s the way it has to be, the content filtering capability is much more important to me.