这几很多网站打不开,开始我还以为是电信的问题.

 打了个电话和电信的MM聊了有半小时 说不是他那边问题.

后来想想可能是路游器问题了,换了个路游还是不行,中间重起陆游不下5次了

 愁死了....

 百度搜了下很多这样的问题但是就是没有一个解决问题的回答....

 最后看到某个人提到MTU值,测试了下自己的MTU值改了下路游,保存 啪下好了,呵呵..

   下面给大家说下MTU值的测试方法...

 ping -f -l 1500 127.0.0.1

C:\WINDOWS>ping -f -l 1500 127.0.0.1
Pinging 127.0.0.1 with 1500 bytes of data:
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Packet needs to be fragmented but DF set.
Ping statistics for 127.0.0.1:
Packets: Sent = 4, Received = 0, Lost = 4 (100% loss), Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

上面的式子中，-l 是 L 的小写（不是 1 ），1500 是我们要测的 MTU 值，结果出现了 Packet needs to be fragmented but DF set. 这个东西，那表示MTU值太大了，你需要更小的 MTU 值才行！好啦！那假设我们使用 1464 来测试时：

C:\WINDOWS>ping -f -l 1464 127.0.0.1
Pinging 127.0.0.1 with 1464 bytes of data:
Reply from 127.0.0.1: bytes=1464 time=10ms TTL=128
Reply from 127.0.0.1: bytes=1464 time<10ms TTL=128
Reply from 127.0.0.1: bytes=1464 time<10ms TTL=128
Reply from 127.0.0.1: bytes=1464 time<10ms TTL=128
Ping statistics for 127.0.0.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 10ms, Average = 2ms
结果出现了回应了！这表示这一个 MTU 值是可行的！不过，强烈建议找出可行的最大 MTU 值！

不过一般的ADSL的MTU值应该都是1492