Why Linux can't visit public net?

[Crucificator]

Michael Schwendt wrote:

>On Thu, 02 Sep 2004 18:02:19 +0800, Edward King wrote:
>
>  
>
>>My computer's OS is Red Hat Linux7.3,I can ping this Linux computer from other computers,but in this Linux computer,I ping publish net,I fount I can't ping it,and I can't visit public net in Red Hat Linux7.3,for example:
>>[root at www root]# ping www.sina.com
>>ping: unknown host www.sina.com
>>
>>Then I try ping gateway,I got follow result:
>>[root at www root]# ping 210.xx.xx.xx
>>PING 210.xx.xx.xx (210.xx.xx.xx) from 210.xx.xx.xx : 56(84) bytes of data.
>>>From 210.xx.xx.xx icmp_seq=1 Packet filtered
>>>From 210.xx.xx.x x icmp_seq=2 Packet filtered
>>>From 210.xx.xx.xx icmp_seq=3 Packet filtered
>>>From 210.xx.xx.xx icmp_seq=4 Packet filtered
>>>From 210.xx.xx.xx icmp_seq=5 Packet filtered
>>
>>--- 210.xx.xx.xx ping statistics ---
>>5 packets transmitted, 0 received, +5 errors, 100% loss, time 4012ms
>>
>>Then I try to ping DNS Server,I found I can't ping it!
>>[root at www root]# ping 210.x.x.x
>>connect: Network is unreachable
>>    
>>
>
>Post the unmodified output of the following commands to add some
>details:
>
>  cat /etc/resolv.conf
>  netstat -nr
>  /sbin/ifconfig -a
>
>Also describe what steps you did to configure your network.
>
>
>  
>
iptables -L wont hurt, too... :)