occurs if an application attempts to bind a socket to an IP address/port
that has already been used for an existing socket, or a socket that
wasn't closed properly, or one that is still in the process of closing.
applications that need to bind multiple sockets to the same port number,
consider using setsockopt (SO_REUSEADDR). Client applications usually need not call bind at all - connect will choose an unused port automatically.
Cannot assign requested address -
The requested address is not valid in its context. This normally results from an attempt to bind to an address that is not valid for the local machine, or connect/sendto an address or port that is not valid for a remote machine (e.g. port 0).
Network is down
A socket operation encountered a dead network. This could indicate a serious failure of the network system (i.e. the protocol stack that the WinSock DLL runs over), the network interface, or the local network itself.
Network is unreachable
A socket operation was attempted to an unreachable network. This usually means the local software knows no route to reach the remote host.
Network dropped connection on reset
The host you were connected to crashed and rebooted. May also be returned by setsockopt if an attempt is made to set SO_KEEPALIVE on a connection that has already failed.
Software caused connection abort
An established connection was aborted by the software in your host machine, possibly due to a data transmission timeout or protocol error
Connection reset by peer
An existing connection was forcibly closed by the remote host. This normally results if the peer application on the remote host is suddenly stopped, the host is rebooted, or the remote host used a "hard close" (see setsockopt for more information on the SO_LINGER option on the remote socket.)
No buffer space available.
An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full.
Socket is already connected
A connect request was made on an already connected socket.
Some implementations also return this error if sendto is called on a connected SOCK_DGRAM socket (For SOCK_STREAM sockets, the
"to" parameter in sendto is ignored), although other implementations treat this as a legal occurrence.
Socket is not connected
A request to send or receive data was disallowed because the socket is not connected and (when sending on a datagram socket using sendto) no address was supplied.
Any other type of operation might also return this error - for example, setsockoptsetting SO_KEEPALIVE if the connection has been reset.
Cannot send after socket shutdown
A request to send or receive data was disallowed because the socket had already been shut down in that direction with a previous shutdown call.
By calling shutdown a partial close of a socket is requested, which is a signal that sending or receiving or both has been discontinued.
Connection timed out
A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
No connection could be made because the target machine actively refused it. This usually results from trying to connect to a service that is inactive on the foreign hostó i.e. one with no server application running.
Host is down
A socket operation failed because the destination host was down.
A socket operation encountered a dead host. Networking activity on the local host has not been initiated. These conditions are more likely to be indicated by the error WSAETIMEDOUT
No route to host
A socket operation was attempted to an unreachable host. This error also occurs when your ISP is intentionally blocking port 25 (the SMTP port) in an attempt to reduce spamming through their systems.
See WSAENETUNREACH 10051
Too many processes
A Windows Sockets implementation may have a limit on the number of applications that may use it simultaneously.
WSAStartup may fail with this error if the limit has been reached.
Network subsystem is unavailable
This error is returned by
WSAStartup if the Windows Sockets implementation cannot function at this time because the underlying system it uses to provide network services is currently unavailable.
Users should check:
that the WINSOCK.DLL file is in the current path,
that the WINSOCK.DLL file is from the same vendor as the underlying protocol stack. They cannot be mixed and matched (WinSock DLLs must be supplied by the same vendor that provided the underlying protocol stack).
that they are not trying to use more than one Windows Sockets implementation simultaneously. If there is more than one WINSOCK DLL on your system, be sure the first one in the path is appropriate for the network subsystem currently loaded.
the Windows Sockets implementation documentation to be sure all necessary components are currently installed and configured correctly.
WINSOCK.DLL version out of range
The current Windows Sockets implementation does not support the Windows Sockets specification version requested by the application.
Check that no old WINSOCK.DLL files are being accessed, or contact the stack vendor to see if an updated WINSOCK.DLL exists.
Successful WSAStartup not yet performed
Either the application hasn't called
The application may be accessing a socket which the current active task does not own (i.e. trying to share a socket between tasks), or WSACleanup has been called too many times.
Graceful shutdown in progress
Returned by recv, WSARecvto indicate the remote party has initiated a graceful shutdown sequence.
Host not found
No such host is known. The name is not an official hostname or alias, or it cannot be found in the database(s) being queried.
This error may also be returned for protocol and service queries, and means the specified name could not be found in the relevant database.
Non-authoritative host not found
This is usually a temporary error during hostname resolution and means that the local server did not receive a response from an authoritative server. A retry at some time later may be successful.
This is a non-recoverable error
This indicates some sort of non-recoverable error occurred during a database lookup.
This may be because the database files (e.g. BSD-compatible HOSTS, SERVICES or PROTOCOLS files) could not be found, or a DNS request was returned by the server with a severe error.
Valid name, no data record of requested type
The requested name is valid and was found in the database, but it does not have the correct associated data being resolved for.
The usual example for this is a hostname -> address translation attempt (using gethostbyname or
WSAAsyncGetHostByName) which uses the DNS (Domain Name Server), and an MX record is returned but no A record - indicating the host itself exists, but is not directly reachable.
WSA_INVALID_HANDLE (OS dependent)
Specified event object handle is invalid
An application attempts to use an event object, but the specified handle is not valid.
WSA_INVALID_PARAMETER (OS dependent)
One or more parameters are invalid
An application used a Windows Sockets function which directly maps to a Win32 function. The Win32 function is indicating a problem with one or more parameters.
Invalid procedure table from service provider
A service provider returned a bogus proc table to WS2_32.DLL. (Usually caused by one or more of the function pointers being NULL.)
(OS dependent) Invalid service provider version number
A service provider returned a version number other than 2.0.
WSA_IO_PENDING (OS dependent)
Overlapped operations will complete later
The application has initiated an overlapped operation which cannot be completed immediately.
A completion indication will be given at a later time when the operation has been completed.
WSA_IO_INCOMPLETE (OS dependent)
Overlapped I/O event object not in signaled state
The application has tried to determine the status of an overlapped operation which is not yet completed.
Applications that use WSAWaitForMultipleEvents in a polling mode to determine when an overlapped operation has completed will get this error code until the operation is complete.
WSA_NOT_ENOUGH_MEMORY (OS dependent)
Insufficient memory available
An application used a Windows Sockets function which directly maps to a Win32 function. The Win32 function is indicating a lack of required memory resources.
Unable to initialize a service provider
Either a service provider's DLL could not be loaded (LoadLibrary failed) or the provider's WSPStartup/NSPStartupfunction failed.
(OS dependent) System call failure
Returned when a system call that should never fail does.
For example, if a call to WaitForMultipleObjects fails or one of the registry functions fails trying to manipulate the protocol/namespace catalogs.
Overlapped operation aborted
An overlapped operation was canceled due to the closure of the socket, or the execution of the SIO_FLUSH command in WSAIoctl.
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Page 1/3 Winsock Error Codes
2/3 User Fixable
There are two basic types
of errors: those
an application user can remedy, and those he cannot and a user should never
see an error that is not user-fixable and list of user-fixable errors.
List of user-fixable errors - This Page 2/3