I have written a VB5 application that pings IP devices by calling
functions in Distinct Corporation's ICMP runtime library.

On my Sniffer I notice that when my application sends a PING echo
request out, my application also sends out a WINS query at UDP port 137
to an IP address which is the reverse of the destination IP address in
the PING echo request packet. For example, if my application is pinging
192.168.249.20, then it is also sending WINS query packets at UDP port
137 to 20.249.168.192. Since the "reverse" address is not on the local
segment and since my routing table does not have a route to this
"reverse" network so my PC sends the packet to the default router. When
the router gets this packet with the "reverse" address it does not know
where to forward so it sends an ICMP destination unreachable (host
unreachable) packet back to my PC.

I ran Distinct Corporation's own ICMP sample program. It behaves in
exactly the same way.

Distinct Corporation said that they implement ICMP according to the RFC
on ICMP ( I assume the RFC is RFC 792). I read the RFC. I do not see any

mention of WINS.

Has anyone encountered the same problem?
Since Distinct Corporation is not quite responsive on resolving this
issue, I am looking at replacing the Distinct Corporation's stuff with
WinSock.
Where can I find information on Winsock programming. Please email your

Thanks