Port DNATting

[Oleg A. Arkhangelsky]

Hello All,

  When I'm trying to do something like this:

  iptables -t nat -I POSTROUTING -p tcp --dport 8080 -j DNAT --to :80

  I get: "iptables: Invalid argument".

  What I want is only to translate destination port of all TCP-packets
  going to some_ip:8080 into some_ip:80. I don't want to change IP. It
  seems that syntax of this command is corrent, but... What is wrong?

  Thanks!

  P.S.: Kernel 2.4.31, iptables v1.3.2

-- 
Best regards,
 Oleg