Exception Msg:No buffer space available (maximum connections reached?): connect [2021-01-04 14:33:50

最近线上遇到windows机器访问其他机器的时候失败的情况。实际就是本地的端口不够用造成的。

 

D:\>netsh interface ipv4 show dynamicportrange protocol=tcp

Protocol tcp Dynamic Port Range

---------------------------------

Start Port : 49152

Number of Ports : 16384

 

D:\>netsh interface ipv4 show tcpstats

MIB-II TCP Statistics

------------------------------------------------------

Timeout Algorithm: Van Jacobson's Algorithm

Minimum Timeout: 10

Maximum Timeout: 4294967295

Maximum Connections: Dynamic

Active Opens: 402947

Passive Opens: 989620

Attempts Failed: 122047

Established Resets: 49384

Currently Established: 135

In Segments: 47651175

Out Segments: 45510477

Retransmitted Segments: 465369

In Errors: 0

Out Resets: 65865

这个能用的端口实际就16384个,可以直接 netstat -atn查看一下每个状态的数量。如果对外做大量的请求会造成本地端口不够用。

 

可以修改一下起始端口:

netsh int ipv4 set dynamicport tcp start=2000 num=63000

netsh int ipv4 set dynamicport udp start=2000 num=63000

netsh int ipv6 set dynamicport tcp start=2000 num=63000

netsh int ipv6 set dynamicport udp start=2000 num=63000

 

 

 

然后修改一下注册表缩短time-wait的时间。

regedit打开注册表，添加

DWORD值

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

“MaxUserPort”=dword:0000fffe

“TcpTimeWaitDelay”=dword:0000005 (缩短为5

 

 

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windows 修改端口数据及连接时间

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