Good morning all.

I have a draytek 2820 and smart monitor running but i am getting in correct reports and stats, When viewing the logs on the smart monitor its reporting several GB in Unknown / Other Traffic. Some "days" has reports as high as 230 + GB of usage. I have checked this againsted the ISP information for the month and the Total "Monthly" usage is only 120GB.... I have the following configuration:
Router Port 1: Main uplink for the office network
Router Port 4: Setup as Sniffing port 1
Smart Monitor Server has 2 Nics.
Nic 1: Main Network Nic which plugs in to the main office network switch.
Nic 2: Plugs directly in to port 4 on the router to capture the sniffed traffic.

Monitored Devices are just the 10 laptops and workstations as the servers have free rain and dont require monitoring, plus i know this excessive traffic is not coming from the servers.....

The Smart monitor is not capturing everything. I know people in the office access internet radio and download files for general use e.g. hotfix for microsoft etc but again this is not being logged in smart monitor. This im not so fussed about but I need these niggles to get resolved so i can present a weekly report to the MD of the company.

We are an IT support company who have pritty much every policy under the sun including an internet usage policy as per an employees contracts etc so everyone knows the internet is monitored but some people are still abusing it like accessing rapishare for illegal file sharing downloads and I need the report to be acurate to avoid any legel loop holes should the matter get taken further. Thanks for any help you can provide.

I have eventually given up on Smartmonitor on the 2820, I find it was too unreliable and would stop monitoring for no reason at all.
I had the 2 x NIC setup like you, so it should be working fine.
I have since purchased some software called WFILTER by IMfirewall, its fairly expensive especially for home use I guess (I bought a 25 user license), but I had a trial for a few weeks and found it to be superb, and much more configurable than smart monitor anyway.
It might be over kill if you want to just monitor, as its purpose is also a internet filter/csm/protocol etc, which works also very well. You can setup email reports etc for a myriad of different metrics as well.

I'm using smartmonitor fairly well on a 2820 with 2x NICs, the one monitoring I found I had to configure with a manual IP and no gateway address so the server wouldn't use it for internet access.
You need to check under System - Setting that it's using the correct NIC otherwise it'll capture / authenticate with the non monitor port NIC. Turning off TCP/IP on the monitor port NIC stops smartmonitor from using the NIC after some time but it doesn't mind the no gateway thing