cat /etc/issue
lsb_release -a
uname -a
cat /etc/*release
repository change
기본 : kr.archive.ubuntu.com(카이스트 운영)
sudo vi /etc/apt/sources.list
:%s/kr.archive.ubuntu.com/ftp.jaist.ac.jp/g
sudo apt-get update
iptables install
apt-get install iptables-persistent