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@www root]# ping www.sina.com ping: unknown host www.sina.com Then I try ping gateway,I got follow result: [root@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@www root]# ping 210.x.x.x connect: Network is unreachable Then I use Windows OS,I configure IP address,gateway and DNS as same as Red Hat Linux7.3,I found I can ping public net and visit public net,like follows: C:\Documents and Settings\Administrator>ping www.sina.com Pinging us.sina.com.cn [66.77.9.79] with 32 bytes of data: Reply from 66.77.9.79: bytes=32 time=190ms TTL=237 Reply from 66.77.9.79: bytes=32 time=181ms TTL=237 Reply from 66.77.9.79: bytes=32 time=190ms TTL=237 Reply from 66.77.9.79: bytes=32 time=181ms TTL=237 Ping statistics for 66.77.9.79: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 181ms, Maximum = 190ms, Average = 185ms Why can't I ping and visit public net under Red Hat Linux7.3? I am a beginer in Linux,please give me detail command. Thanks in advance! Best regards, Edward -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list