http://ftp.daum.net/ubuntu/
https://mirror.misakamikoto.network/ubuntu-ports/
https://mirror.kakao.com/ubuntu/
https://ftp.harukasan.org/ubuntu/
https://ftp.harukasan.org/ubuntu-ports/
https://mirror.anigil.com/ubuntu/
https://mirror.misakamikoto.network/ubuntu/
https://mirror.yongbok.net/ubuntu/
https://ftp.lanet.kr/ubuntu-ports/
https://ftp.lanet.kr/ubuntu/
http://archive.ubuntu.com/ubuntu/