fix binding port error on Windows

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Having installed Hyper-V on my machine, I found that I couldn’t start up Tomcat.

It warns me that port 1099 is in use.

And here is my debugging note.

  1. First of all, check whether there are some programs occupying the port.

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    netstat -ano | find "1099"

    Unfortunately, I found nothing.

  2. Secondly, check the dynamic port range

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    netsh int ipv4 show dynamicport tcp

    which might give an output like this:

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    协议 tcp 动态端口范围
    ---------------------------------
    启动端口        : 1024
    端口数          : 13977

    It seems that installing Hyper-V will change the value and you could change this back to the default value by executing the command below

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    netsh int ipv4 set dynamicportrange tcp start=49152 num=16384

    However, it seems that there are no effects.

  3. Third, check whether the port is reserved by Hyper-V

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    netsh interface ipv4 show excludedportrange protocol=tcp

    which might give an output like this:

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    协议 tcp 端口排除范围

    开始端口    结束端口
    ----------    --------
          1066        1165
          1366        1465
          1666        1765
          5357        5357
          5700        5700
          8155        8254
          8884        8884
         12437       12536
         14493       14592
         50000       50059     *

    * - 管理的端口排除。

    And we can see that port 1099 is in the excluded list and we can only change tomcat’s port or disable Hyper-V to solve this problem.

    After searching online, I have founded an undocumented reg key which can prevent Hyper-V from occupying those ports.

    Just run the following code and then reboot.

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    reg add HKLM\SYSTEM\CurrentControlSet\Services\hns\State /v EnableExcludedPortRange /d 0 /f
    netsh int ipv4 set dynamicport tcp start=49152 num=16384