Network scanner

[via Digitalmars-d-learn]

On Tuesday, 11 November 2014 at 16:04:21 UTC, ketmar via 
Digitalmars-d-learn wrote:
> On Tue, 11 Nov 2014 15:35:28 +0000
> RuZzz via Digitalmars-d-learn 
> <digitalmars-d-learn at puremagic.com> wrote:
>
>> netstat reports that the socket is in the TIME_WAIT or 
>> CLOSE_WAIT state.
> i'm not an expert in winsock, but did you tried to set 
> SO_LINGER to
> "off"?
Closed ports stay in state WAIT for quite a while.
If SO_LINGER=off doesn't help try to tune some Windows TCP 
parameters:
- reduce TcpTimedWaitDelay from 120 to 30 seconds
- use ports above 5000
- bigger port hash table

Remember to reboot after stetting these registry values:

REGEDIT4

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters]
"TcpTimedWaitDelay"=dword:0000001e
"MaxUserPort"=dword:fffe
"MaxHashTableSize"=dword:ffff
"NumTcbTablePartitions"=dword:8