Linux: How to port forwarding with iptables between 2 hosts on different networks?

I'm almost desperate... I've been reading for about 2 days iptables forwarding examples and I cannot do a simple port forwarding. I got 2 machines on different networks. server1 (S1 with ip 195.21.2.41) is at my house and server2 (s2 with ip 10.234.141.126) is at Amazon EC2.

I need to forward all the traffic that goes to s2 to s1. I tried this:

flushing all rules, activate kernel parameter to forward, add a postrouting and prerouting rule

iptables -F -t nat
iptables -F
echo 1 > /proc/sys/net/ipv4/ip_forward 
iptables -t nat -A POSTROUTING -d 195.21.2.41 -j MASQUERADE
iptables -t nat -A PREROUTING -i eth0 -d 10.234.141.126 -p tcp --dport 80 -j DNAT --to 195.21.2.41

optionally i also added:

iptables -A FORWARD -p tcp -i eth0 -d 195.21.2.41 --dport 80 -j ACCEPT

Then i tried:

telnet 10.234.141.126 80

But didn't work. Why the hell this isnt working?

UPDATE: take a look at some tests:

[root@ip-10-234-141-216 ~]# telnet 195.21.2.41 80
Trying 195.21.2.41...
Connected to 195.21.2.41.
Escape character is '^]'.

[root@ip-10-234-141-216 ~]# iptables -F -t nat
[root@ip-10-234-141-216 ~]# iptables -F
[root@ip-10-234-141-216 ~]# echo 1 > /proc/sys/net/ipv4/ip_forward 
[root@ip-10-234-141-216 ~]# /sbin/iptables -t nat -A PREROUTING -i eth0 -p tcp -d 10.234.141.126 --dport 80 -j DNAT --to-destination 195.21.2.41
[root@ip-10-234-141-226 ~]# /sbin/iptables -t nat -A POSTROUTING -j MASQUERADE
[root@ip-10-234-141-216 ~]# /sbin/iptables -A FORWARD -i eth0 -p tcp --dport 80 -j ACCEPT
[root@ip-10-234-141-216 ~]# 
[root@ip-10-234-141-216 ~]# telnet 10.234.141.126 80
Trying 10.234.141.126...
telnet: connect to address 10.234.141.126: Connection refused

UPDATE 2 route output:

[root@ip-10-234-141-216 ~]# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.234.141.0    0.0.0.0         255.255.254.0   U     0      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     1002   0        0 eth0
0.0.0.0         10.234.141.1    0.0.0.0         UG    0      0        0 eth0

Answer

If you just need to redirect all incoming traffic to a specified port forwarded to your another machine try rinetd instead of iptables. It's a traffic redirection server.