Solaris 10 using snoop to capture packets.
When I telnet to an unused IP address, and wait for the connection attempt to time out, everything behaves as expected (SYNs sent several times until connection establishment time out exceeded, then telnet quits).
When do the same thing, but cancel the attempt before it reaches the time out, with control-c, the last packet has a RSET.
Is this done for a reason? Maybe the network stack is assuming that the SYNs were successful, even if the SYN-ACK didn't come back, so it sends a RSET to keep the remote system from being left half-open?
I had read Stevens TCP/IP Illustrated, Vol 1 a long time ago, and I don't recall this being discussed (I checked with a quick google, but didn't dig up the book).