I want to do shoutcast radio.
i have adsl modem with static ip and internal lan interface
on nat (adsl) i did port forwarding to my linux router(
my shoutcast radio on computer in internal network( with ip adress
on linux router i have two lan interfaces (eth0 and eth1
i have did iptables rules on linux router(

iptables -t nat -A PREROUTING -p tcp --dport 8000 -j DNAT --to-destination

iptables -t nat -A POSTROUTING -d -p tcp --dport 8000 -j MASQUERADE

but it doesn't work.

if i try to connect to my server via linux router from my network it works well(music plaing).
telnet 8000
if i try to connect to my server via internet it doesn't work.
telnet 8000

OS cent os 5.4
radiocast ->Shoutcast