I don't know why my server can't be ping url, I think it can't be access to internet; Yesterday I did delete all of text at hosts.deny and hosts.allow. Is it problem came from it?
[root test]# ping
Usage: ping [-LRUbdfnqrvV] [-c count] [-i interval] [-w wait]
[-p pattern] [-s packetsize] [-t ttl] [-I interface address]
[ -T timestamp option ] [ -Q tos ] host
[root test]# ping
www.yahoo.com
ping: unknown host
www.yahoo.com
Thanks