🚀 go-pugleaf

"johnG" <whatis@email.com> wrote in message 
news:4804eb76$1@newsgroups.borland.com...

> Does it broadcast to all subnets accessible by a specific (physical
> network) network adapter, or all subnets across all adapters?

Using "255.255.255.255" as the destination IP will send the data on all 
physical adapters.  This is documented by Microsoft:

    sendto() function
    http://msdn2.microsoft.com/en-us/library/ms740148.aspx

    "To send a broadcast (on a SOCK_DGRAM only), the address pointed to by 
the to parameter can be constructed to contain the special IPv4 address 
INADDR_BROADCAST (defined in Winsock2.h), together with the intended port 
number. If the address pointed to by the to parameter contains the 
INADDR_BROADCAST address and intended port, then the broadcast will be sent 
out on all interfaces to that port.

    If the broadcast should be sent out only on a specific interface, then 
the address pointed to by the to parameter should contain the subnet 
broadcast address for the interface and the intended port. For example, an 
IPv4 network address of 192.168.1.0 with a subnet mask of 255.255.255.0 
would use a subnet broadcast address of 192.168.1.255."

INADDR_BROADCAST is defined as $FFFFFFFF, aka "255.255.255.255".

> Sorry, using indy 9.0.50,but is upgrading the only way to
> prevent sending messages across all network adapters?

Yes, unless you manually re-write Broadcast() and then re-compile Indy.


Gambit