MIB_TCP6ROW2 structure (tcpmib.h)

Article
07/27/2022

The MIB_TCP6ROW2 structure contains information that describes an IPv6 TCP connection.

Syntax

typedef struct _MIB_TCP6ROW2 {
  IN6_ADDR                     LocalAddr;
  DWORD                        dwLocalScopeId;
  DWORD                        dwLocalPort;
  IN6_ADDR                     RemoteAddr;
  DWORD                        dwRemoteScopeId;
  DWORD                        dwRemotePort;
  MIB_TCP_STATE                State;
  DWORD                        dwOwningPid;
  TCP_CONNECTION_OFFLOAD_STATE dwOffloadState;
} MIB_TCP6ROW2, *PMIB_TCP6ROW2;

Members

LocalAddr

Type: IN6_ADDR

The local IPv6 address for the TCP connection on the local computer. A value of zero indicates the listener can accept a connection on any interface.

dwLocalScopeId

Type: DWORD

The local scope ID for the TCP connection on the local computer.

dwLocalPort

Type: DWORD

The local port number in network byte order for the TCP connection on the local computer.

The maximum size of an IP port number is 16 bits, so only the lower 16 bits should be used. The upper 16 bits may contain uninitialized data.

RemoteAddr

Type: IN6_ADDR

The IPv6 address for the TCP connection on the remote computer. When the State member is MIB_TCP_STATE_LISTEN, this value has no meaning.

dwRemoteScopeId

Type: DWORD

The remote scope ID for the TCP connection on the remote computer. When the State member is MIB_TCP_STATE_LISTEN, this value has no meaning.

dwRemotePort

Type: DWORD

The remote port number in network byte order for the TCP connection on the remote computer. When the State member is MIB_TCP_STATE_LISTEN, this value has no meaning.

The maximum size of an IP port number is 16 bits, so only the lower 16 bits should be used. The upper 16 bits may contain uninitialized data.

State

Type: MIB_TCP_STATE

The state of the TCP connection. This member can be one of the values from the MIB_TCP_STATE enumeration type defined in the Tcpmib.h header file.

Value	Meaning
MIB_TCP_STATE_CLOSED 1	The TCP connection is in the CLOSED state that represents no connection state at all.
MIB_TCP_STATE_LISTEN 2	The TCP connection is in the LISTEN state waiting for a connection request from any remote TCP and port.
MIB_TCP_STATE_SYN_SENT 3	The TCP connection is in the SYN-SENT state waiting for a matching connection request after having sent a connection request (SYN packet).
MIB_TCP_STATE_SYN_RCVD 4	The TCP connection is in the SYN-RECEIVED state waiting for a confirming connection request acknowledgment after having both received and sent a connection request (SYN packet).
MIB_TCP_STATE_ESTAB 5	The TCP connection is in the ESTABLISHED state that represents an open connection, data received can be delivered to the user. This is the normal state for the data transfer phase of the TCP connection.
MIB_TCP_STATE_FIN_WAIT1 6	The TCP connection is FIN-WAIT-1 state waiting for a connection termination request from the remote TCP, or an acknowledgment of the connection termination request previously sent.
MIB_TCP_STATE_FIN_WAIT2 7	The TCP connection is FIN-WAIT-1 state waiting for a connection termination request from the remote TCP.
MIB_TCP_STATE_CLOSE_WAIT 8	The TCP connection is in the CLOSE-WAIT state waiting for a connection termination request from the local user.
MIB_TCP_STATE_CLOSING 9	The TCP connection is in the CLOSING state waiting for a connection termination request acknowledgment from the remote TCP.
MIB_TCP_STATE_LAST_ACK 10	The TCP connection is in the LAST-ACK state waiting for an acknowledgment of the connection termination request previously sent to the remote TCP (which includes an acknowledgment of its connection termination request).
MIB_TCP_STATE_TIME_WAIT 11	The TCP connection is in the TIME-WAIT state waiting for enough time to pass to be sure the remote TCP received the acknowledgment of its connection termination request.
MIB_TCP_STATE_DELETE_TCB 12	The TCP connection is in the delete TCB state that represents the deletion of the Transmission Control Block (TCB), a data structure used to maintain information on each TCP entry.

dwOwningPid

Type: DWORD

The PID of the process that issued a context bind for this TCP connection.

dwOffloadState

Type: TCP_CONNECTION_OFFLOAD_STATE

The offload state for this TCP connection. This parameter can be one of the enumeration values for the TCP_CONNECTION_OFFLOAD_STATE defined in the Tcpmib.h header.

Remarks

The MIB_TCP6ROW2 structure is defined on Windows Vista and later.

The GetTcp6Table2 function retrieves the IPv6 TCP connection table on the local computer and returns this information in a MIB_TCP6TABLE2 structure.

An array of MIB_TCP6ROW2 structures are contained in the MIB_TCP6TABLE2 structure.

The State member indicates the state of the TCP entry in a TCP state diagram. A TCP connection progresses through a series of states during its lifetime. The states are: LISTEN, SYN-SENT, SYN-RECEIVED, ESTABLISHED, FIN-WAIT-1, FIN-WAIT-2, CLOSE-WAIT, CLOSING, LAST-ACK, TIME-WAIT, and the fictional state CLOSED. The CLOSED state is fictional because it represents the state when there is no Transmission Control Block, and therefore, no connection. The TCP protocol is described in RFC 793. For more information, see http://www.ietf.org/rfc/rfc793.txt.

The dwLocalPort, and dwRemotePort members are in network byte order. In order to use the dwLocalPort or dwRemotePort members, the ntohs or inet_ntoa functions in Windows Sockets or similar functions may be needed.

The dwLocalScopeId, and dwRemoteScopeId members are in network byte order. In order to use the dwLocalScopeId or dwRemoteScopeId members, the ntohl or inet_ntoa functions in Windows Sockets or similar functions may be needed.

The LocalAddr and RemoteAddr members are stored in in6_addr structures. The RtlIpv6AddressToString or RtlIpv6AddressToStringEx functions may be used to convert the IPv6 address in the LocalAddr or RemoteAddr members to a string without loading the Windows Sockets DLL.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2008 [desktop apps only]
Header	tcpmib.h (include Iphlpapi.h)

MIB_TCP6ROW2 structure (tcpmib.h)

Syntax

Members

Remarks

Requirements

See also

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