解决Mac网速越来越慢(飞一般的感觉)

1.设置MTU
--->系统偏好设置
 --->网络
  --->高级
   --->硬件
    --->配置改为：手动
     --->MTU范围(1280-1500)
         设置为:1490

2.测试出最适合的MTU值(可以查看丢包率即可)
# sudo ping -l 1490 -f www.baidu.com
--- www.a.shifen.com ping statistics ---
29165 packets transmitted, 27582 packets received, 5.4% packet loss
round-trip min/avg/max/stddev = 12.373/114.813/166.011/12.999 ms