C6300v2 logs contents not as expected

D

ear Netgear expert/support

I just got a C6300v2 and activated successfully by xfinity. it works great. one of the reason I use it to replace the xfinity router is it says it can log the website that has been visited. here is the quote from the user manual. 

at page 78 of C6300v2_All_MSOs_UM_EN.pdf 

View Logs of Cable Modem Router Activity

The log is a detailed record of the websites you accessed or attempted to access and
other cable modem router actions. Up to 256 entries are stored in the log. Log entries
display only when keyword blocking is enabled, and no log entries are made for the
trusted user.

4. Select ADVANCED > Administration > Logs.
The Logs page displays the following information:
• Date and time. The date and time the log entry was recorded.
• Source IP. The IP address of the initiating device for this log entry.
• Target address. The name or IP address of the website or news group visited or
to which access was attempted.
• Action. The action that occurred, such as whether Internet access was blocked
or allowed.

almost all target and source in the log are all 0.  

Do I need to change some setup or the xfinity played some trick to masked the real ip address?

if I couldn't log the detail web ip address, don't think it is a good idea to use this modem to replace xfinity's. 

Thanks for help. 

David