"unable to access 'https://github.com/Homebrew/homebrew/': Could not resolve host: github.com"

[cici1989]

abcdedeMBP:~ chenfeichi$ ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
==> This script will install:
/usr/local/bin/brew
/usr/local/Library/...
/usr/local/share/man/man1/brew.1

Press RETURN to continue or any other key to abort
==> Downloading and installing Homebrew...
fatal: unable to access 'https://github.com/Homebrew/homebrew/': Could not resolve host: github.com
Failed during: git fetch origin master:refs/remotes/origin/master -n --depth=1