关于Linux和Windows中的MTU

红色为命令和注释、修改后的MTU，蓝色的为修改前的MTU

Linux 中设置 MTU 值的三种方法：

[root@localhost ~]# ifconfig   // 查看网卡信息

eth0      Link encap:Ethernet  HWaddr 00: 0C :29: 0C :B8: 6A  

          inet addr:192.168.10.1  Bcast:192.168.10.255  Mask:255.255.255.0

          inet6 addr: fe80:: 20c :29ff:fe 0c :b 86a /64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:1948 errors:0 dropped:0 overruns:0 frame:0

          TX packets:87 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:208651 (203.7 KiB)  TX bytes:17782 (17.3 KiB)

          Interrupt:169 Base address:0x2000

 

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:7442 errors:0 dropped:0 overruns:0 frame:0

          TX packets:7442 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:0

          RX bytes:9177752 (8.7 MiB)  TX bytes:9177752 (8.7 MiB)

 

第一种：

[root@localhost ~]# ifconfig eth0 mtu 1492

eth0      Link encap:Ethernet  HWaddr 00: 0C :29: 0C :B8: 6A  

          inet addr:192.168.10.1  Bcast:192.168.10.255  Mask:255.255.255.0

          inet6 addr: fe80:: 20c :29ff:fe 0c :b 86a /64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1492  Metric:1

          RX packets:1948 errors:0 dropped:0 overruns:0 frame:0

          TX packets:87 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:208651 (203.7 KiB)  TX bytes:17782 (17.3 KiB)

          Interrupt:169 Base address:0x2000

 

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:7442 errors:0 dropped:0 overruns:0 frame:0

          TX packets:7442 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:0

          RX bytes:9177752 (8.7 MiB)  TX bytes:9177752 (8.7 MiB)

[root@localhost ~]#

 

第二种方法：

[root@localhost ~]# ip link list

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue

    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000

    link/ether 00: 0c :29: 0c :b8: 6a brd ff:ff:ff:ff:ff:ff

3: sit0: <NOARP> mtu 1480 qdisc noop

    link/sit 0.0.0 .0 brd 0.0.0.0

[root@localhost ~]# ip link set dev eth0 mtu 1492

[root@localhost ~]# ip link list

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue

    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1492 qdisc pfifo_fast

qlen 1000

    link/ether 00: 0c :29: 0c :b8: 6a brd ff:ff:ff:ff:ff:ff

3: sit0: <NOARP> mtu 1480 qdisc noop

link/sit 0.0.0 .0 brd 0.0.0.0

[root@localhost ~]#

第三种方法：

[root@localhost ~]# vi /etc/sysconfig/network-scripts/ifcfg-eth0

[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0

# Advanced Micro Devices [AMD] 79c 970 [PCnet32 LANCE]

DEVICE=eth0

BOOTPROTO=none

HWADDR=00: 0C :29: 0C :B8: 6A

ONBOOT=yes

NETMASK=255.255.255.0

IPADDR=192.168.10.1

TYPE=Ethernet

USERCTL=no

IPV6INIT=no

PEERDNS=yes

[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0

# Advanced Micro Devices [AMD] 79c 970 [PCnet32 LANCE]

DEVICE=eth0

MTU=1492

BOOTPROTO=none

HWADDR=00: 0C :29: 0C :B8: 6A

ONBOOT=yes

NETMASK=255.255.255.0

IPADDR=192.168.10.1

TYPE=Ethernet

USERCTL=no

IPV6INIT=no

PEERDNS=yes

[root@localhost ~]#

 

最后重启网络服务

[root@localhost ~]#service network restart eth0

Windows xp\vista\win 7 中测试 MTU

 

 

修改注册表中以下这项，

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services \Tcpip\Parameters\Interfaces\

 

 

在这项下有几个网卡信息，你点击每个看右边 IPAddress 项，对应自己网卡 IP 的就是的再 输入数值。

 

至于为什么 Windows 中 MTU 是 1492 ，是因为我的是 ADSL 拨号(pppoe)上网的，不是 1492 可能有些网页无法游览。 MTU 最大值在以太网帧中是 1500 字节。