Why do traffic reports on the CacheFlow appliance show a blank destination field?

A blank 'Destination' field in the traffic report is caused by non-HTTP traffic that is intercepted by the CacheFlow appliance. This is rarely observed in a production CacheFlow appliance because such traffic is extremely low in volume and would not make it to the top 100 sites which you can view from the traffic report.

Typically, you can only observe such entry in a targetted caching environment or a test/lab environment

This can be simulated consistently using  the steps below:
 1) telnet <random IP> 80
 2) key in random character