2013年3月3日
网络管理
一、IP地址
1、查看IP地址
[root@desktop7 ~]# ifconfig eth0 |head -n 5
eth0 Link encap:Ethernet HWaddr 50:46:5D:71:C2:F1
inet6 addr: fe80::5246:5dff:fe71:c2f1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:81 errors:0 dropped:0 overruns:0 frame:0
TX packets:104 errors:0 dropped:0 overruns:0 carrier:0
2、修改IP地址
[root@desktop7 ~]# ifconfig eth0 192.168.0.211
[root@desktop7 ~]# ifconfig eth0 |head -n 5
eth0 Link encap:Ethernet HWaddr 50:46:5D:71:C2:F1
inet addr:192.168.0.211 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::5246:5dff:fe71:c2f1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:342 errors:0 dropped:0 overruns:0 frame:0
3、修改子网掩码
[root@desktop7 ~]# ifconfig eth0 192.168.0.211 netmask 255.255.0.0
[root@desktop7 ~]# ifconfig eth0 |head -n 3
eth0 Link encap:Ethernet HWaddr 50:46:5D:71:C2:F1
inet addr:192.168.0.211 Bcast:192.168.255.255 Mask:255.255.0.0
inet6 addr: fe80::5246:5dff:fe71:c2f1/64 Scope:Link
为便于验证，改为另一网段
[root@desktop7 ~]# ifconfig eth0 192.168.0.211 netmask 255.255.255.0
[root@desktop7 ~]# ifconfig eth0 |head -n 3
eth0 Link encap:Ethernet HWaddr 50:46:5D:71:C2:F1
inet addr:192.168.0.211 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::5246:5dff:fe71:c2f1/64 Scope:Link
[root@desktop7 ~]#
4、关闭网卡
关闭前
[root@desktop7 ~]# ifconfig eth0 |head -n 5
eth0 Link encap:Ethernet HWaddr 50:46:5D:71:C2:F1
inet addr:192.168.0.211 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::5246:5dff:fe71:c2f1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:342 errors:0 dropped:0 overruns:0 frame:0
关闭网卡
[root@desktop7 ~]# ifconfig eth0 down
关闭后
[root@desktop7 ~]# ifconfig eth0 |head -n 5
eth0 Link encap:Ethernet HWaddr 50:46:5D:71:C2:F1
inet addr:192.168.0.211 Bcast:192.168.0.255 Mask:255.255.255.0
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:342 errors:0 dropped:0 overruns:0 frame:0
TX packets:214 errors:0 dropped:0 overruns:0 carrier:0
[root@desktop7 ~]#
5、打开网卡
[root@desktop7 ~]# ifconfig eth0 up
[root@desktop7 ~]# ifconfig eth0 |head -n 5
eth0 Link encap:Ethernet HWaddr 50:46:5D:71:C2:F1
inet addr:192.168.0.211 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::5246:5dff:fe71:c2f1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:342 errors:0 dropped:0 overruns:0 frame:0
[root@desktop7 ~]#
6、简单方式关闭、打开网卡
（1）关闭网卡
[root@desktop7 ~]# ifdown eth0
[root@desktop7 ~]# ifconfig eth0 |head -n 5
eth0 Link encap:Ethernet HWaddr 50:46:5D:71:C2:F1
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:342 errors:0 dropped:0 overruns:0 frame:0
TX packets:241 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
（2）打开网卡
[root@desktop7 ~]# ifup eth0
[root@desktop7 ~]# ifconfig eth0 |head -5
eth0 Link encap:Ethernet HWaddr 50:46:5D:71:C2:F1
inet6 addr: fe80::5246:5dff:fe71:c2f1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:342 errors:0 dropped:0 overruns:0 frame:0
TX packets:257 errors:0 dropped:0 overruns:0 carrier:0
[root@desktop7 ~]#
7、查看本机所有网卡（NIC）信息
[root@desktop7 ~]# ifconfig -a
br0 Link encap:Ethernet HWaddr 50:46:5D:71:C2:F1
inet addr:192.168.0.7 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::5246:5dff:fe71:c2f1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:342 errors:0 dropped:0 overruns:0 frame:0
TX packets:125 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:37321 (36.4 KiB) TX bytes:22797 (22.2 KiB)
eth0 Link encap:Ethernet HWaddr 50:46:5D:71:C2:F1
inet6 addr: fe80::5246:5dff:fe71:c2f1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:342 errors:0 dropped:0 overruns:0 frame:0
TX packets:257 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:42133 (41.1 KiB) TX bytes:60062 (58.6 KiB)
Interrupt:233 Base address:0x6000
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:16436 Metric:1
RX packets:2742 errors:0 dropped:0 overruns:0 frame:0
TX packets:2742 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:4120944 (3.9 MiB) TX bytes:4120944 (3.9 MiB)
sit0 Link encap:IPv6-in-IPv4
NOARP MTU:1480 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
virbr0 Link encap:Ethernet HWaddr 00:00:00:00:00:00
inet addr:192.168.122.1 Bcast:192.168.122.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:20 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:3617 (3.5 KiB)
vnet0 Link encap:Ethernet HWaddr FE:54:00:00:00:CF
inet6 addr: fe80::fc54:ff:fe00:cf/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:6 errors:0 dropped:0 overruns:0 frame:0
TX packets:305 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:384 (384.0 b) TX bytes:47407 (46.2 KiB)
vnet1 Link encap:Ethernet HWaddr FE:54:00:00:00:6B
inet6 addr: fe80::fc54:ff:fe00:6b/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:6 errors:0 dropped:0 overruns:0 frame:0
TX packets:305 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:384 (384.0 b) TX bytes:47226 (46.1 KiB)
[root@desktop7 ~]#
二、网络服务
1、查看网络状态
[root@desktop7 ~]# service network sdatus
Usage: /etc/init.d/network {start|stop|restart|reload|status}
[root@desktop7 ~]# /etc/init.d/network status
Configured devices:
lo br0 eth0
Currently active devices:
lo eth0 br0 virbr0 vnet0 vnet1
[root@desktop7 ~]#
2、停止网络服务
[root@desktop7 ~]# service network stop
Shutting down interface br0: [ OK ]
Shutting down interface eth0: [ OK ]
Shutting down loopback interface: [ OK ]
Disabling IPv4 packet forwarding: net.ipv4.ip_forward = 0
[ OK ]
查看网络状态
[root@desktop7 ~]# service network status
Configured devices:
lo br0 eth0
Currently active devices:
virbr0 vnet0 vnet1
[root@desktop7 ~]#
3、重启网络服务
[root@desktop7 ~]# service network restart
Shutting down loopback interface: [ OK ]
Bringing up loopback interface: [ OK ]
Bringing up interface eth0: [ OK ]
Bringing up interface br0:
Determining IP information for br0... done.
[ OK ]
查看网络状态
[root@desktop7 ~]# service network status
Configured devices:
lo br0 eth0
Currently active devices:
lo eth0 br0 virbr0 vnet0 vnet1
[root@desktop7 ~]#
三、网关
1、查看网关状态
[root@desktop7 ~]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 * 255.255.255.0 U 0 0 0 br0
192.168.122.0 * 255.255.255.0 U 0 0 0 virbr0
169.254.0.0 * 255.255.0.0 U 0 0 0 br0
default 192.168.0.254 0.0.0.0 UG 0 0 0 br0
用数字显示
[root@desktop7 ~]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 br0
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 br0
0.0.0.0 192.168.0.254 0.0.0.0 UG 0 0 0 br0
[root@desktop7 ~]#
2、删除多余网关
[root@desktop7 ~]# route del -net 169.254.0.0/16
[root@desktop7 ~]# route del -net 192.168.122.0/24
[root@desktop7 ~]# route del default gw 192.168.0.254
查看状态
[root@desktop7 ~]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 br0
[root@desktop7 ~]#
3、新增网关
（1）添加默认网关
[root@desktop7 ~]# route add default gw 192.168.0.253
（2）添加172.16.0.0/16网段网关
[root@desktop7 ~]# route add -net 172.16.0.0/16 gw 192.168.0.11
（3）添加10.0.0.0/8网段网关
[root@desktop7 ~]# route add -net 10.0.0.0/8 gw 192.168.0.22
查看状态
[root@desktop7 ~]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 br0
172.16.0.0 192.168.0.11 255.255.0.0 UG 0 0 0 br0
10.0.0.0 192.168.0.22 255.0.0.0 UG 0 0 0 br0
0.0.0.0 192.168.0.253 0.0.0.0 UG 0 0 0 br0
[root@desktop7 ~]#
（4）最后删除多余网段路由
[root@desktop7 ~]# route del -net 172.16.0.0/16
[root@desktop7 ~]# route del -net 10.0.0.0/8
[root@desktop7 ~]# route del default gw 192.168.0.253
查看状态
[root@desktop7 ~]# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 br0
[root@desktop7 ~]#
四、网关配置文件
[root@desktop7 ~]# vi /etc/sysconfig/network-scripts/route-eth0
GATEWAY0=192.168.0.253
NETMASK0=0.0.0.0
DDRESS0=0.0.0.0
GATEWAY1=192.168.0.254
NETMASK1=255.255.0.0
ADDRESS1=172.16.0.0
另外一种书写方式
[root@desktop211 ~]# vim /etc/sysconfig/network-scripts/route-eth0
172.16.0.0/16 via 192.168.0.254
0.0.0.0 via 192.168.0.253
五、DNS配置文件
[root@desktop7 ~]# vi /etc/resolv.conf
; generated by /sbin/dhclient-script
search example.com
nameserver 202.106.0.20
nameserver 8.8.8.8
六、主机名
1、查看主机名
[root@desktop7 ~]# hostname
desktop7.example.com
2、修改主机名
[root@desktop7 ~]# hostname desktop211.example.com
查看修改结果
[root@desktop7 ~]# hostname
desktop211.example.com
[root@desktop7 ~]#
注销，主机名生效
[root@desktop211 ~]# hostname
desktop211.example.com
[root@desktop211 ~]#
改回原主机名
[root@desktop211 ~]# hostname desktop7.example.com
[root@desktop211 ~]#
[root@desktop7 ~]# hostname
desktop7.example.com
[root@desktop7 ~]#
3、主机名配置文件
[root@desktop7 ~]# vi /etc/sysconfig/network
NETWORKING=yes
NETWORKING_IPV6=yes
HOSTNAME=desktop7.example.com
注意：未修改配置文件，单纯用命令修改主机名注销后虽然能生效，但重启主机后仍为原主机名
[root@desktop211 ~]# hostname
desktop211.example.com
[root@desktop211 ~]# vi /etc/sysconfig/network
NETWORKING=yes
NETWORKING_IPV6=yes
HOSTNAME=desktop7.example.com
反之，只修改配置文件，不用命令修改主机名，重启主机后新主机名生效
七、IP
IP配置文件
[root@desktop211 ~]# vim /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=dhcp
ONBOOT=yes
BRIDGE=br0
NETMASK=255.255.255.0
GATEWAY=192.168.0.253
DNS1=202.106.0.20
DNS2=8.8.8.8