failed to open stream: Network is unreachable

なんだこのエラー？

$ php -v
PHP 4.4.4-8+etch4 (cli) (built: Jun 30 2007 21:02:54)
Copyright (c) 1997-2006 The PHP Group
Zend Engine v1.3.0, Copyright (c) 1998-2004 Zend Technologies
$
$ php -r "print file_get_contents('http://www.google.com/');"
Warning: file_get_contents(http://www.google.com/): failed to open stream: Network is unreachable in Command line code on line 1
$
$ perl -MLWP::Simple -e 'getprint "http://www.google.com/";'
//->htmlソースがずらずら