Korean user, disabled changing dns server to

I used SK broadband FTTH 150mbps (Korea ISP) and model name RUSH-337AC

I want to change dns servers to but is forced and locked.

how to use is in my case just impossible?

Sadly, it may be blocked by some ISPs due to copyright issue by Korean government.
but you can try another ip, is not blocked yet.
you must remember that maybe it will be blocked too.

SKB가 공유기 기본 DNS 서버의 변경을 바꿀 수 없도록 펌웨어상에서 수정해 놓은 것 같습니다. 이 부분은 SK 브로드밴트측에 문의해 보시는게 좋을 것 같습니다.

공유기에서 바꿀 수 없다면, 사용중인 기기에서 (스마트폰이나 컴퓨터) 직접 DNS 설정을 바꾸는 방법도 있습니다.

It seems that SKB had block user changing main DNS. You need to contact to SK Broadband.

If you can’t change the DNS setting on router, you can try to change DNS setting on your devices. (like Smartphone, Computer)