IPInterfaceInfo structure (tcpioctl.h)

[This structure may be altered or unavailable in future versions of Windows.]

The IPInterfaceInfo structure contains information about a specific IP interface, returned by the IOCTL_TCP_QUERY_INFORMATION_EX control code.

Syntax

typedef struct IPInterfaceInfo {
  ulong iii_flags;
  ulong iii_mtu;
  ulong iii_speed;
  ulong iii_addrlength;
  uchar iii_addr[1];
} IPInterfaceInfo;

Members

iii_flags

The types of communication supported on this interface. This member can be one or more of the following values.

Value	Meaning
1	Point-to-point.
2	Point-to-multipoint.
4	Unidirectional communication.

iii_mtu

The maximum transmission unit: the size, in bytes, of the largest datagram that can be sent and/or received on the interface.

iii_speed

An estimate of the interface's current bandwidth in bits per second. For interfaces that do not vary in bandwidth or for which no accurate estimation can be made, this member contains the nominal bandwidth.

iii_addrlength

The length, in bytes, of the IP address associated with this interface that is contained in the iii_addr member.

iii_addr[1]

The IP address associated with this interface. In Windows Vista, this is the physical address.

Remarks

This is a variable-length structure whose size depends on whether the iii_addr member contains an IPv4 or IPv6 address. To allocate a buffer large enough to contain it safely, use the size:

sizeof(IPInterfaceInfo) + MAX_PHYSADDR_SIZE

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Header	tcpioctl.h

See also

IOCTL_TCP_QUERY_INFORMATION_EX

Management Information Base Reference