linux网络设置问题 ping: unknown host www.baidu.com
在尝试简历建立 连接时：
[cf@yun01 Desktop]$ ssh yun@yun01
ssh: connect to host yun01 port 22: Network is unreachable
失败了 ，校验一下网络
[root@yun01 Desktop]# ping www.baidu.com
ping: unknown host www.baidu.com
建立网络连接有问题
ifconfig查看
eth1 Link encap:Ethernet HWaddr 00:0C:29:17:4E:E0
inet6 addr: fe80::20c:29ff:fe17:4ee0/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4 errors:0 dropped:0 overruns:0 frame:0
TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:240 (240.0 b) TX bytes:258 (258.0 b)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:812 errors:0 dropped:0 overruns:0 frame:0
TX packets:812 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:61588 (60.1 KiB) TX bytes:61588 (60.1 KiB)
缺少 net addr 。检查发现网络未连接，打开网络连接之后 再次查看
[root@yun01 Desktop]# ifconfig
eth1 Link encap:Ethernet HWaddr 00:0C:29:17:4E:E0
inet addr:192.168.1.115 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fe17:4ee0/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:4 errors:0 dropped:0 overruns:0 frame:0
TX packets:5 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:240 (240.0 b) TX bytes:378 (378.0 b)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:824 errors:0 dropped:0 overruns:0 frame:0
TX packets:824 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:62452 (60.9 KiB) TX bytes:62452 (60.9 KiB)
正常分配 IP ，但尝试ping百度
[root@yun01 Desktop]# ping www.baidu.com
ping: unknown host www.baidu.com
ping 8.8.8.8 时 就能建立正常的
[root@yun01 Desktop]# ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=3 ttl=35 time=111 ms
检查发现 DNS有问题，尚未配置，参照网上的DNS配置：
sudo vi /etc/resolv.conf
nameserver 8.8.8.8
再次 ping
[root@yun01 Desktop]# ping www.baidu.com
PING www.a.shifen.com (119.75.217.109) 56(84) bytes of data.
64 bytes from 119.75.217.109: icmp_seq=1 ttl=53 time=33.6 ms
64 bytes from 119.75.217.109: icmp_seq=2 ttl=53 time=36.4 ms
在linux终端中正常连接了。