每天一个linux命令（27）：ifconfig命令

ゞ浴缸里的玫瑰 2023-07-12 14:08 13阅读 0赞

ifconfig(interfaces config)。通常需要以root身份登录或使用sudo来使用ifconfig工具

ifconfig 命令用来查看和配置网络设备。当网络环境发生改变时可通过此命令对网络进行相应的配置。

备注：用ifconfig命令配置的网卡信息，在网卡重启后机器重启后，配置就不存在。要想将上述的配置信息永远的存的电脑里，那就要修改网卡的配置文件了。

### ifconfig常见命令参数 ###

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   <td> <p>1</p> <p>2</p> <p>3</p> <p>4</p> <p>5</p> <p>6</p> <p>7</p> <p>8</p> <p>9</p> <p>10</p> <p>11</p> <p>12</p> <p>13</p> <p>14</p> </td> 
   <td> <p><code>Usage:</code></p> <p><code>&nbsp;&nbsp;</code><code>ifconfig</code>&nbsp;<code>[-a] [-</code><code>v</code><code>] [-s] &lt;interface&gt; [[&lt;AF&gt;] &lt;address&gt;]</code></p> <p><code>&nbsp;&nbsp;</code><code>[add &lt;address&gt;[/&lt;prefixlen&gt;]]</code></p> <p><code>&nbsp;&nbsp;</code><code>[del &lt;address&gt;[/&lt;prefixlen&gt;]]</code></p> <p><code>&nbsp;&nbsp;</code><code>[[-]broadcast [&lt;address&gt;]]&nbsp; [[-]pointopoint [&lt;address&gt;]]</code></p> <p><code>&nbsp;&nbsp;</code><code>[netmask &lt;address&gt;]&nbsp; [dstaddr &lt;address&gt;]&nbsp; [tunnel &lt;address&gt;]</code></p> <p><code>&nbsp;&nbsp;</code><code>[outfill &lt;NN&gt;] [keepalive &lt;NN&gt;]</code></p> <p><code>&nbsp;&nbsp;</code><code>[hw &lt;HW&gt; &lt;address&gt;]&nbsp; [metric &lt;NN&gt;]&nbsp; [mtu &lt;NN&gt;]</code></p> <p><code>&nbsp;&nbsp;</code><code>[[-]trailers]&nbsp; [[-]arp]&nbsp; [[-]allmulti]</code></p> <p><code>&nbsp;&nbsp;</code><code>[multicast]&nbsp; [[-]promisc]</code></p> <p><code>&nbsp;&nbsp;</code><code>[mem_start &lt;NN&gt;]&nbsp; [io_addr &lt;NN&gt;]&nbsp; [irq &lt;NN&gt;]&nbsp; [media &lt;</code><code>type</code><code>&gt;]</code></p> <p><code>&nbsp;&nbsp;</code><code>[txqueuelen &lt;NN&gt;]</code></p> <p><code>&nbsp;&nbsp;</code><code>[[-]dynamic]</code></p> <p><code>&nbsp;&nbsp;</code><code>[up|down] ...</code></p> </td> 
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### 常用的命令展示 ###

查看当前系统有几个网卡

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>[root@localhost ~]</code><code># ifconfig |grep eth* | awk -F '[ ]+' '{print $1}'</code></p> </td> 
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![image][]

启动关闭指定网卡

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> <p>2</p> <p>3</p> <p>4</p> <p>5</p> </td> 
   <td> <p><code>ifconfig</code>&nbsp;<code>eth0 up&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </code><code># 启动 &lt;br&gt;ifcfg etho up&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; # 启动</code></p> <p><code>ifconfig</code>&nbsp;<code>eth0 down&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </code><code># 关闭&lt;br&gt;ifcfg eth0 down&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; # 关闭</code></p> <p><code>ifconfig</code>&nbsp;<code>eth0 reload&nbsp;&nbsp;&nbsp; </code><code># 重启</code></p> <p><code>说明： </code><code>ifconfig</code>&nbsp;<code>eth0 up 为启动网卡eth0 ；</code><code>ifconfig</code>&nbsp;<code>eth0 down 为关闭网卡eth0。 </code></p> <p><code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</code><code>ssh</code><code>登陆linux服务器操作要小心，关闭了就不能开启了，除非你有多网卡。</code></p> </td> 
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</table>

![image][image 1]

为网卡配置和删除IPv6地址【临时生效，永久生效需要更改配置文件】

eth2网卡配置文件： /etc/sysconfig/network-scripts/ifcfg-eth2

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> <p>2</p> <p>3</p> </td> 
   <td> <p><code>ifconfig</code>&nbsp;<code>eth0 add 33ffe:3240:800:1005::2</code><code>/64</code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<code># 为网卡eth0配置IPv6地址 </code></p> <p>&nbsp;</p> <p><code>ifconfig</code>&nbsp;<code>eth0 del 33ffe:3240:800:1005::2</code><code>/64</code>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<code># 为网卡eth0删除IPv6地址 </code></p> </td> 
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为网卡配置和删除IPv4地址【临时生效，永久生效需要更改配置文件】

eth2网卡配置文件： /etc/sysconfig/network-scripts/ifcfg-eth2

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>[root@localhost ~]</code><code># ifconfig eth0 192.168.25.166 netmask 255.255.255.0 up</code></p> </td> 
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<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>[root@localhost ~]</code><code># ifconfig eth0 192.168.25.166/24 up&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 【效果同上】</code></p> </td> 
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<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>[root@localhost ~]</code><code># ip addr add 192.168.25.166/24&nbsp; dev eth0&nbsp; 【效果同上】</code></p> </td> 
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![image][image 2]

<table> 
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   <td> <p><code>[root@localhost ~]</code><code># ifconfig eth0:ws 192.168.25.166 netmask 255.255.255.0 up</code></p> </td> 
  </tr> 
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</table>

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>[root@localhost ~]</code><code># ifconfig eth0:ws 192.168.25.166/24 up&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 【效果同上】</code></p> </td> 
  </tr> 
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</table>

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>[root@localhost ~]</code><code># ip addr add 192.168.25.166/24&nbsp; dev eth0:ws&nbsp; 【效果同上】</code></p> </td> 
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![image][image 3]

<table> 
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   <td> <p><code>[root@localhost ~]</code><code>#ifconfig eth0:ws&nbsp; 192.168.25.166 netmask 255.255.255.0 down</code></p> </td> 
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<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>[root@localhost ~]</code><code>#ifconfig eth0:ws&nbsp; 192.168.25.166/24 dwon&nbsp;&nbsp;&nbsp;&nbsp; 【效果同上】</code></p> </td> 
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<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>[root@localhost ~]</code><code># ip addr del 192.168.25.166/24&nbsp; dev eth0:ws&nbsp; 【效果同上】</code></p> </td> 
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![image][image 4]

用ifconfig修改MAC地址

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>ifconfig</code>&nbsp;<code>eth0 down </code><code>//</code><code>关闭网卡</code></p> </td> 
  </tr> 
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</table>

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>ifconfig</code>&nbsp;<code>eth0 hw ether 00:AA:BB:CC:DD:EE </code><code>//</code><code>修改MAC地址</code></p> </td> 
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<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>ifconfig</code>&nbsp;<code>eth0 up&nbsp;&nbsp;&nbsp; </code><code>//</code><code>启动网卡</code></p> </td> 
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启用和关闭ARP协议

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> <p>2</p> <p>3</p> </td> 
   <td> <p><code>ifconfig</code>&nbsp;<code>eth0:ws arp </code></p> <p>&nbsp;</p> <p><code>ifconfig</code>&nbsp;<code>eth0:ws -arp </code></p> </td> 
  </tr> 
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设置最大传输单元

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> </td> 
   <td> <p><code>ifconfig</code>&nbsp;<code>eth0 mtu 1500</code></p> </td> 
  </tr> 
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### 网卡配置文件 ###

网卡eth2对应： /etc/sysconfig/network-scripts/ifcfg-eth2

网卡eth0对应： /etc/sysconfig/network-scripts/ifcfg-eth0

根据网卡名称找对应的文件名称即可

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> <p>2</p> <p>3</p> <p>4</p> <p>5</p> <p>6</p> <p>7</p> <p>8</p> <p>9</p> <p>10</p> <p>11</p> <p>12</p> <p>13</p> <p>14</p> <p>15</p> <p>16</p> <p>17</p> </td> 
   <td> <p><code>[root@localhost omd]</code><code># cat /etc/sysconfig/network-scripts/ifcfg-eth2 </code></p> <p><code>HWADDR=00:0c:29:E4:35:5D</code></p> <p><code>TYPE=Ethernet</code></p> <p><code>BOOTPROTO=none</code></p> <p><code>IPADDR=192.168.25.133</code></p> <p><code>PREFIX=24</code></p> <p><code>GATEWAY=192.168.25.2</code></p> <p><code>DNS1=192.168.25.2</code></p> <p><code>DEFROUTE=</code><code>yes</code></p> <p><code>IPV4_FAILURE_FATAL=</code><code>yes</code></p> <p><code>IPV6INIT=no</code></p> <p><code>NAME=</code><code>"eth2"</code></p> <p><code>UUID=6e6f9829-0737-4943-ab21-61d6173ba8c4</code></p> <p><code>ONBOOT=</code><code>yes</code></p> <p><code>LAST_CONNECT=1438160743</code></p> <p><code>DEVICE=eth2</code></p> <p><code>USERCTL=no</code></p> </td> 
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### 网卡的硬件信息 ###

网卡出现乱序，多是因为Mac和网卡名称不一致导致，需要更改此网卡的硬件信息

<table> 
 <tbody> 
  <tr> 
   <td> <p>1</p> <p>2</p> <p>3</p> <p>4</p> <p>5</p> <p>6</p> <p>7</p> <p>8</p> <p>9</p> <p>10</p> <p>11</p> <p>12</p> </td> 
   <td> <p><code>[root@localhost ~]</code><code># cat /etc/udev/rules.d/70-persistent-net.rules</code></p> <p><code># This file was automatically generated by the /lib/udev/write_net_rules</code></p> <p><code># program, run by the persistent-net-generator.rules rules file.</code></p> <p><code>#</code></p> <p><code># You can modify it, as long as you keep each rule on a single</code></p> <p><code># line, and change only the value of the NAME= key.</code></p> <p>&nbsp;</p> <p><code># PCI device 0x1022:0x2000 (vmxnet)</code></p> <p><code>#SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:0c:29:cc:16:f0", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"</code></p> <p>&nbsp;</p> <p><code># PCI device 0x1022:0x2000 (vmxnet)</code></p> <p><code>SUBSYSTEM==</code><code>"net"</code><code>, ACTION==</code><code>"add"</code><code>, DRIVERS==</code><code>"?*"</code><code>, ATTR{address}==</code><code>"00:0c:29:e4:35:5d"</code><code>, ATTR{ </code><code>type</code><code>}==</code><code>"1"</code><code>, KERNEL==</code><code>"eth*"</code><code>, NAME=</code><code>"eth2"</code></p> </td> 
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[image 3]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pbWFnZXMyMDE4LmNuYmxvZ3MuY29tL2Jsb2cvNTE5NjA4LzIwMTgwNy81MTk2MDgtMjAxODA3MDcwOTQ2MzQ1MTMtOTA5NzU2NzY0LnBuZw?x-oss-process=image/format,png
[image 4]: https://imgconvert.csdnimg.cn/aHR0cHM6Ly9pbWFnZXMyMDE4LmNuYmxvZ3MuY29tL2Jsb2cvNTE5NjA4LzIwMTgwNy81MTk2MDgtMjAxODA3MDcwOTQ2MzUyMjAtMTY3MDgwNjAzNy5wbmc?x-oss-process=image/format,png