I have several machines on my LAN. Most of them Ubuntu based. Router has DD-WRT (v3.0-r33675M kongac Release: 11/03/17) firmware.
I have set DHCP to serve network settings for all my computers. Router has been set to use 18.104.22.168 for DNS server.
Now I want to verify my computers are using quad9 for DNS, but I am unable to do so. My computers see only the router and are not aware which DNS it is using.
For example, command (in Ubuntu)
sudo netstat -l --inet -n -v -p | grep :53 | grep -i udp
udp 0 0 127.0.1.1:53 0.0.0.0:*
So I cannot verify I am using quad9 in this manner.
Router does not recognize this command, so I cannot verify DNS setting that way.
I have tried things in this post in computer and in DD-WRT command line, but none help: What DNS servers am I using?
How can I properly verify I am using quad9 for DNS?