原本的 Ubuntu Linux 在做套件更新時，會依照地區所在別，切換到不同的 Server，以臺灣為例是 tw.archive.ubuntu.com
查看一下這一台 Server 的資訊
$ host tw.archive.ubuntu.com
tw.archive.ubuntu.com is an alias for ubuntu.stu.edu.tw.
ubuntu.stu.edu.tw is an alias for ftp.stu.edu.tw.
ftp.stu.edu.tw has address 120.119.118.1
ftp.stu.edu.tw has IPv6 address 2001:e10:c41:eeee::1
因為 Server 是在臺灣，所以連線速度都還不會太慢[@more@]但安全性更新(security)，則是 security.ubuntu.com
$ host security.ubuntu.com
security.ubuntu.com has address 91.189.91.14
security.ubuntu.com has address 91.189.91.15
security.ubuntu.com has address 91.189.91.23
security.ubuntu.com has address 91.189.91.13
security.ubuntu.com has address 91.189.92.201
security.ubuntu.com has address 91.189.88.149
security.ubuntu.com has address 91.189.92.200
security.ubuntu.com has address 91.189.91.24
security.ubuntu.com has IPv6 address 2001:67c:1562::17
security.ubuntu.com has IPv6 address 2001:67c:1562::13
security.ubuntu.com has IPv6 address 2001:67c:1562::16
security.ubuntu.com has IPv6 address 2001:67c:1562::14
security.ubuntu.com has IPv6 address 2001:67c:1562::15
security.ubuntu.com has IPv6 address 2001:67c:1360:8c01::18
security.ubuntu.com has IPv6 address 2001:67c:1360:8c01::19
這一台 Server 看起來則不像是在臺灣，所以連線速度有時候會很慢
底下將更新的 Server 都改成國家高速網路中心
$ sudo sed -i ‘s/tw.archive.ubuntu.com/free.nchc.org.tw/g’ /etc/apt/sources.list
$ sudo sed -i ‘s/security.ubuntu.com/free.nchc.org.tw/g’ /etc/apt/sources.list
清除所有的
$ sudo apt-get clean all
更新套件庫
$ sudo apt-get update