一 更改国内源
1 首先备份官方源，以免设置错误可恢复。
$ sudo cp /etc/apt/sources.list /etc/apt/sources.list.back
2 用编辑器打开 /etc/apt/sources.list文件。
$ sudo nano /etc/apt/sources.list
3 删除原有的源，在编辑器中添加新源（阿里源）。如图所示：
deb http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse
二 设置固定IP
原文：http://www.cnblogs.com/spkljl/p/5349122.html