主要用途：
1、查看网络接口设置： ifconfig –a或ifconfig 网络接口 –a
2、网络配置 ifconfig  网络接口  [add/del]  IP地址  netmask  子网掩码 例：ifocnfig eth0 10.2.3.4 [netmask 255.255.255.0]
3、网络接口的激活/关闭 格式：ifconfig 网络接口 up/down
配置dns
建立/etc/resolv.conf文件，在里面写入DNS服务器地址
配置主机名
配置/etc/sysconfig/network文件，同时使用hostname 修改主机名
使用例子：

复制代码 代码如下:
[root@twin0898 sysconfig]# cat network
network          networking/      network-scripts/
[root@twin0898 sysconfig]# cat network
NETWORKING=yes
GATEWAY=125.39.149.1
HOSTNAME=twin0898
NETWORKING_IPV6=no

通用格式：
1、到网络的网关 route  add/delete  -net  目标网络  netmask  掩码   gw  网关地址  [dev  网络接口]
2、到单一主机的网关 route  add/delete  -host  目标主机  gw  网关地址  [dev  网络接口]
3、添加默认网关： route  add  default  gw  网关地址 检查主机路由表：route，netstat -nr
// 总结如下：
1、网络配置检查：ifconfig -a
2、连通性检查：ping、traceroute
3、路由表检查：route或netstat –nr
4、DNS客户端运行状态检查：nslookup
// 使用例子如下
// ifconfig -a

复制代码 代码如下:
root@CinemaTest2:/usr/local/jdk# ifconfig -a
eth0      Link encap:Ethernet  HWaddr b8:ac:6f:38:10:c6 
          inet addr:192.168.232.127  Bcast:192.168.232.255  Mask:255.255.255.0
          inet6 addr: fe80::baac:6fff:fe38:10c6/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:42918159 errors:0 dropped:0 overruns:0 frame:0
          TX packets:40893832 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:30644395811 (30.6 GB)  TX bytes:30932951131 (30.9 GB)
          Interrupt:16

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:917 errors:0 dropped:0 overruns:0 frame:0
          TX packets:917 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:81417 (81.4 KB)  TX bytes:81417 (81.4 KB)

// ping vip.jb51.net
复制代码 代码如下:
PING movie.kankan.co.sandai.net (114.80.189.60) 56(84) bytes of data.
64 bytes from 114.80.189.60: icmp_seq=1 ttl=54 time=31.2 ms
64 bytes from 114.80.189.60: icmp_seq=2 ttl=54 time=29.9 ms
64 bytes from 114.80.189.60: icmp_seq=3 ttl=54 time=31.1 ms
64 bytes from 114.80.189.60: icmp_seq=4 ttl=54 time=30.5 ms
64 bytes from 114.80.189.60: icmp_seq=5 ttl=54 time=31.4 ms
64 bytes from 114.80.189.60: icmp_seq=6 ttl=54 time=32.6 ms
64 bytes from 114.80.189.60: icmp_seq=7 ttl=54 time=30.8 ms
64 bytes from 114.80.189.60: icmp_seq=8 ttl=54 time=30.9 ms
64 bytes from 114.80.189.60: icmp_seq=9 ttl=54 time=32.0 ms
64 bytes from 114.80.189.60: icmp_seq=10 ttl=54 time=31.3 ms
64 bytes from 114.80.189.60: icmp_seq=11 ttl=54 time=31.3 ms
64 bytes from 114.80.189.60: icmp_seq=12 ttl=54 time=30.3 ms

--- movie.kankan.co.sandai.net ping statistics ---
12 packets transmitted, 12 received, 0% packet loss, time 11004ms
rtt min/avg/max/mdev = 29.954/31.148/32.608/0.704 ms

// netstat -nr
复制代码 代码如下:
root@CinemaTest2:/usr/local/jdk# netstat -nr
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
0.0.0.0         192.168.232.2   0.0.0.0         UG        0 0          0 eth0
192.168.232.0   0.0.0.0         255.255.255.0   U         0 0          0 eth0

// nslookup vip.jb51.net
复制代码 代码如下:
root@CinemaTest2:/etc# nslookup vip.jb51.net
Server:         192.168.8.150
Address:        192.168.8.150#53

Non-authoritative answer:
vip.jb51.net  canonical name = movie.jb51.net.
movie.jb51.net        canonical name = movie.kankan.co.sandai.net.
Name:   movie.kankan.co.sandai.net
Address: 114.80.189.60
Name:   movie.kankan.co.sandai.net
Address: 119.147.41.209