From: josef.moellers@invalid.invalid   
      
   Hi,   
      
   I'm trying to teach a small AtMega32 with an ENC28J60 TCP/IP, to use the   
   setup as a COM-to-LAN adapter.   
   I have successfully implemented (rudimentary versions) of DHCP, ARP and   
   ICMP and have now started to process TCP packets.   
   Note: I *do* know there's ethersex and friends out there, but I get   
   greater satisfaction when "suddenly" the ARP-table of my notebook shows   
   the data of my AtMega ;-) Maybe once this is running, I'll rebase on   
   ethersex, but, at this time, I'm having lots of fun.   
      
   As a first step, I try to just refuse a connection. I process the   
   request, extract source addresses (MAC and IP) and source and   
   destination ports and the packet's sequence number and then build a   
   reply with the correct acknowledgement number (sequence number plus 1)   
   and RST and ACK set. Wireshark says it's OK.   
   However, when I telnet to the AtMega, telnet doesn't stop trying to   
   connect while when I telnet to another Linux box, telnet immediately   
   gives up after the first ACK|RST and tells me   
   "telnet: Unable to connect to remote host: Connection refused"   
      
   When I compare the two RST packets, I can see no obvious difference,   
   other than   
   a) trailing ff's (Linux) vs. trailing 00's (AtMega)   
   b) an IP "Identification" field of 0 (Linux) vs. 5 (AtMega)   
      
   What makes telnet give up on the Linux box and not give up on the AtMega?   
      
   Thanks,   
      
   Josef   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)