From Dig command, we can see that some of the Google service (e.g. gstatics.com) shares the same IP groups with YouTube websites(as the following images show). Since the both websites are using the same IP group, using Keyword Block and Web Content Filter to block YouTube may also block some of the Google services at the same time. Therefore, it is suggested to use the LAN DNS to block YouTube.
1. Create a LAN DNS profile: Go to LAN >> LAN DNS, click Add to configure profile details.
Input youtube.com as Domain Name.
Click Add then input “www.youtube.com" as CNAME.
Input an invalid IP address, such as 22.214.171.124.
2. Enable DNS Redirection: Go to LAN >> General Setup, in a LAN profile, enable its DNS Redirection.
3. After completing the configurations above, please run “ipconfig/flushdns” on the Windows Command Prompt to ensure local computer will send new DNS query for www.youtube.com
In this example, when PC is sending DNS query to ask who is www.youtube.com, Vigor3900 will respond the IP of www.youtube.comis 126.96.36.199. Since 188.8.131.52 is not the real IP of www.youtube.com, the PC cannot access it now.