To get the currently active connections count you could Powershell it:
$a=gwmi -class Win32_PerfFormattedData_Tcpip_TCPv4 |select ConnectionsEstablished
$a.ConnectionsEstablished
Note that there is also a ConnectionsActive in the same class which displays cumulative rather than current connection count. Here is a class reference.
As detailed in this MSDN blog post there are two system tweaks you can use to increase the system tolerance when client port exhaustion is a threat:
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Increase the upper range of ephemeral ports that are dynamically allocated to client TCP/IP socket connections.
- Start Registry Editor.
Browse to, and then click the following key in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
On the Edit
menu, click New
, DWORD Value
, and then add the following registry value to increase the number of ephemeral ports that can by dynamically allocated to clients:
Value name MaxUserPort
Value data <Enter a decimal value between 5000 and 65534 here>
You must restart your computer for this change to take effect. Increasing the range of ephemeral ports used for client TCP/IP connections consumes Windows kernel memory. Do not increase the upper limit for this setting to a value higher than is required to accommodate client application socket connections so as to minimize unnecessary consumption of Windows kernel memory.
Reduce the client TCP/IP socket connection timeout value from the default value of 240 seconds
Browse to, and then click the following key in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
On the Edit
menu, click New
, DWORD Value
, and then add the following registry value to reduce the length of time that a connection stays in the TIME_WAIT
state when the connection is being closed. While a connection is in the TIME_WAIT
state, the socket pair cannot be reused:
Value name TcpTimedWaitDelay
Value data <Enter a decimal value between 30 and 240 here>
You must restart your computer for this change to take effect. The valid range of this value is 30 through 300 (decimal). The default value is 240.
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