There's been a little confusion about raw sockets and Windows XP SP2. Hopefully, this little entry from the "Changes in functionality..." doc (see my last blog entry for an URL to the doc) should explain things a little better:

A very small number of Windows applications make use of raw IP sockets, which provide an industry-standard way for applications to create TCP/IP packets with fewer integrity and security checks by the TCP/IP stack. The Windows implementation of TCP/IP still supports receiving traffic on raw IP sockets. However, the ability to send traffic over raw sockets has been restricted in two ways:

  • TCP data cannot be sent over raw sockets.
  • UDP datagrams with invalid source addresses cannot be sent over raw sockets. The IP source address for any outgoing UDP datagram must exist on a network interface or the datagram is dropped.