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：
[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
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
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
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
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