[tcpdump] Proxy delegate refusing connexion ?
- by simtris
Hi guys,
I'm a little disapointed ! 
My aim was to build a VERY simple smtp proxy under debian to handle mail from a port (51234) and forward it to the standard 25 port.
I compile and install a "delegate" witch can handle easily that.
It's working very well like that :
  delegated SERVER="smtp://anotherSmtpServer:25" -P51234
The strange thing is, it's working on my virtual test machine and on the dedicated server in local but I can't manage to use it trought internet. I test it like that.
  telnet [mySrv] 51234
Of course, no firewal, no deny host, no ined/xined, the service delegated is listening on the right port ... 
2 clues :
The port is answering trought internet with nmap as "51234/tcp open   tcpwrapped"
have a look at the tcpdump following :
  22:50:54.864398 IP [myIp].1699  [mySrv].51234: S 2486749330:2486749330(0) win 65535 
  
  22:50:54.864449 IP [mySrv].51234  [myIp].1699: S 2486963525:2486963525(0) ack 2486749331 win 5840 
  
  22:50:54.948169 IP [myIp].1699  [mySrv].51234: . ack 1 win 64240
  
  22:50:54.965134 IP [mySrv].43554  [myIp].auth: S 2485396968:2485396968(0) win 5840 
  
  22:50:55.243128 IP [myIp]  [mySrv]: ICMP [myIp] tcp port auth unreachable, length 68
  
  22:50:55.249646 IP [mySrv].51234  [myIp].1699: F 1:1(0) ack 1 win 46
  
  22:50:55.309853 IP [myIp].1699  [mySrv].51234: . ack 2 win 64240
  
  22:50:55.310126 IP [myIp].1699  [mySrv].51234: F 1:1(0) ack 2 win 64240
  
  22:50:55.310137 IP [mySrv].51234  [myIp].1699: . ack 2 win 46
The part "auth" seems suspect to me but didn't ring a bell.
I could certaily do with some help. Thx a lot !