网络原理及基本设置
识别网络设备网卡种类与逻辑别名ifconfig或dmesg命令
识别网络设备
开机时Linux读取/etc/modprobe.conf文件设定、并根据这些设定决定载入哪些网卡的驱动程序模块为了方便系统的管理和维护，网络设定文件和脚本中都会使用网卡的逻辑名来引用网卡系统中的第1个网卡的逻辑名是eth0在/etc/modprobe.conf文件中将这些网卡的逻辑名对应到系统所监测到的特定网卡好处是可减轻管理员管理和维护系统的工作量
网卡种类与逻辑别名
网卡种类与逻辑别名的对应关系：
Ethernet卡：eth为字首后跟数字编号作逻辑名Token Ring卡：tr为字首后跟数字编号作逻辑名FDDI卡：fddi为字首后跟数字编号作逻辑名PPP：ppp为字首后跟数字编号作逻辑名 每个网卡上都有唯一的编号、该编号由网卡制造商编号和网卡出厂时的序列号两部分组成的：
ifconfig或dmesg命令
可使用ifconfig或dmesg命令查看系统上网卡编号ifconfig中if是interface的缩写、config是configure前6个字母dmesg中d是device第1个字母、mesg是message缩写使用ifconfig命令获取所有正在启用的网卡信息:在以上命令显示结果中HWadd是Hardware Address（硬件地址）的缩写、紧跟其后的6组由冒号分隔的十六进制数字为该网卡的硬件地址
[root@dog network-scripts]
[root@dog network-scripts]
[root@dog network-scripts]
正在关闭接口 eth0： 设备状态：3 （断开连接）
[确定
]
关闭环回接口：
[确定
]
弹出环回接口：
[确定
]
弹出界面 eth0： 活跃连接状态：激活中
活跃连接路径：
/org
/freedesktop
/NetworkManager
/ActiveConnection
/3
状态：已激活
连接被激活
[确定
]
[root@dog network-scripts]
eth0 Link encap:Ethernet HWaddr 00:0C:29:02:55:0F
inet addr:192
.168
.40
.132 Bcast:192
.168
.40
.255 Mask:255
.255
.255
.0
inet6 addr: fe80::20c:29ff:fe02:550f
/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2669 errors:0 dropped:0 overruns:0 frame:0
TX packets:128 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:177342
(173
.1 KiB
) TX bytes:14196
(13
.8 KiB
)
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:16 errors:0 dropped:0 overruns:0 frame:0
TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1104
(1
.0 KiB
) TX bytes:1104
(1
.0 KiB
)
[root@dog network-scripts]
正在关闭接口 eth0： 设备状态：3 （断开连接）
[确定
]
关闭环回接口：
[确定
]
弹出环回接口：
[确定
]
弹出界面 eth0： 活跃连接状态：已激活
活跃连接路径：
/org
/freedesktop
/NetworkManager
/ActiveConnection
/4
[确定
]
[root@dog network-scripts]
eth0 Link encap:Ethernet HWaddr 00:0C:29:02:55:0F
inet addr:192
.168
.40
.132 Bcast:192
.168
.40
.255 Mask:255
.255
.255
.0
inet6 addr: fe80::20c:29ff:fe02:550f
/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2893 errors:0 dropped:0 overruns:0 frame:0
TX packets:188 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:192377
(187
.8 KiB
) TX bytes:19191
(18
.7 KiB
)
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:136 errors:0 dropped:0 overruns:0 frame:0
TX packets:136 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:10512
(10
.2 KiB
) TX bytes:10512
(10
.2 KiB
)
[root@dog network-scripts]
PING www
.a
.shifen
.com
(61
.135
.169
.121
) 56
(84
) bytes of
data.
64 bytes
from 61
.135
.169
.121: icmp_seq=1 ttl=128 time=99
.3 ms
64 bytes
from 61
.135
.169
.121: icmp_seq=2 ttl=128 time=88
.3 ms
^Z
[7
]+ Stopped ping www
.baidu
.com
You have new mail in
/var/spool
/mail
/root
[root@dog network-scripts]
设备状态：3 （断开连接）
[root@dog network-scripts]
eth0 Link encap:Ethernet HWaddr 00:0C:29:02:55:0F
inet6 addr: fe80::20c:29ff:fe02:550f
/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:11278 errors:0 dropped:0 overruns:0 frame:0
TX packets:712 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:780819
(762
.5 KiB
) TX bytes:70035
(68
.3 KiB
)
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:148 errors:0 dropped:0 overruns:0 frame:0
TX packets:148 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:11446
(11
.1 KiB
) TX bytes:11446
(11
.1 KiB
)
[root@dog network-scripts]
活跃连接状态：激活中
活跃连接路径：
/org
/freedesktop
/NetworkManager
/ActiveConnection
/15
状态：已激活
连接被激活
[root@dog network-scripts]
eth0 Link encap:Ethernet HWaddr 00:0C:29:02:55:0F
inet addr:192
.168
.40
.132 Bcast:192
.168
.40
.255 Mask:255
.255
.255
.0
inet6 addr: fe80::20c:29ff:fe02:550f
/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:11281 errors:0 dropped:0 overruns:0 frame:0
TX packets:717 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:781297
(762
.9 KiB
) TX bytes:70665
(69
.0 KiB
)
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:148 errors:0 dropped:0 overruns:0 frame:0
TX packets:148 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:11446
(11
.1 KiB
) TX bytes:11446
(11
.1 KiB
)
[root@dog network-scripts]
[root@dog network-scripts]
ifcfg
-eth0 ifdown
-isdn ifup
-aliases ifup
-plusb init
.ipv6
-global
ifcfg
-lo ifdown
-post ifup
-bnep ifup
-post net
.hotplug
ifdown ifdown
-ppp ifup
-eth ifup
-ppp network
-functions
ifdown
-bnep ifdown
-routes ifup
-ippp ifup
-routes network
-functions
-ipv6
ifdown
-eth ifdown
-sit ifup
-ipv6 ifup
-sit
ifdown
-ippp ifdown
-tunnel ifup
-isdn ifup
-tunnel
ifdown
-ipv6 ifup ifup
-plip ifup
-wireless
[root@dog network-scripts]
-rw
-r-
-r-
-. 1 root root 302 6月 1 22:38 ifcfg
-eth0
-rw
-r-
-r-
-. 1 root root 254 4月 27 2018 ifcfg
-lo
[root@dog network-scripts]
DVICE=eth0
TYPE=Ethernet
UUID=8f0e6033
-75c6
-4efa
-a7f9
-24a358fcf65e
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=dhcp
IPADDR=192
.168
.40
.110
NETMASK=255
.255
.255
.0
GATEWAY=192
.168
.40
.2
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
HWADDR=00:0C:29:02:55:0F
PREFIX=24
DEFROUTE=yes
NAME=
"System eth0"
LAST_CONNECT=1591064817
[root@dog network-scripts]
[root@dog network-scripts]
ifcfg
-eth0 ifdown
-post ifup
-ippp ifup
-tunnel
ifcfg
-eth0
.bak ifdown
-ppp ifup
-ipv6 ifup
-wireless
ifcfg
-lo ifdown
-routes ifup
-isdn init
.ipv6
-global
ifdown ifdown
-sit ifup
-plip net
.hotplug
ifdown
-bnep ifdown
-tunnel ifup
-plusb network
-functions
ifdown
-eth ifup ifup
-post network
-functions
-ipv6
ifdown
-ippp ifup
-aliases ifup
-ppp
ifdown
-ipv6 ifup
-bnep ifup
-routes
ifdown
-isdn ifup
-eth ifup
-sit
[root@dog network-scripts]
rm：是否删除普通文件
"ifcfg-eth0"？y
[root@dog network-scripts]
ifcfg
-eth0
.bak ifcfg
-lo
