Re: socket in use

["Steve Richter" <srichter@xxxxxxxxxxxxx>]

>
>Steve,
>
>This is from the IBM Infocenter page for the 'setsockopt()' API call,
>under "usage notes":
>
>    6. When a TCP connection is closed for a socket using the AF_INET
>       address family, the port associated with that connection is not
>       made available until twice the Maximum Segment Life (MSL) time in
>       seconds has passed. The MSL time is approximately 2 minutes. The
>       SO_REUSEADDR option allows a bind() to succeed when requesting a
>       port that is being held during this time frame.
>       This can be especially useful if a server is abruptly ended and
>       restarted.
>
>You can read the whole thing online at:
>
>http://publib.boulder.ibm.com/pubs/html/as400/v4r5/ic2924/info/apis/ssocko.
htm
>
>
>Sincerely,
>
>Scott Klement
>Mayor Of The Socket People
>


Mr Mayor and other socket people,

I saw that item when I was reading my sockets manual. It struck me as rather
odd. Any idea as to its origin?

Steve Richter
A mere socket rookie.




>
>On Wed, 25 Jul 2001, Steve Richter wrote:
>
>> Socket people,
>>
>> I am getting an intermitent "socket in use" error in my as400 socket
server
>> pgm as I test my win95 to as400 socket code.
>>
>> Even though the shutdown( ) and close( ) functions run without error, the
>> next time I run my pgm, a "socket in use" error occurs on the Bind( )
stmt.
>> And NetStat shows my prev use of the socket still in a listen state on
the
>> socket.
>>
>> By using SetSockOpt( ), I think I have solved the problem. But varying
the
>> use of shutdown( ) and close( ) also reduced the frequency of the in use
>> condition.
>>
>> My question: Why does the correct use of shutdown( ) and close( ) not
always
>> free the socket?
>>
>> Is there some timeout value that can be set?
>>
>> Also, is there an api equivalent of NetStat?  When my pgm gets an "in
use"
>> return code, can it find out what job is using the socket?
>>
>> And,  Can my pgm forcefully free up a socket that it knows is not really
in
>> use?
>>
>>
>> Thanks,
>>
>> Steve Richter
>>
>
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