port redirecting

[idan72]

Hi,

I am running my application that include many servers.
I want to modify the destination port of receiving packets according to the destination ip.
I try to use iptables but the problem is that when I redirect the port it also modify the destination address.

Is there other way to do this ?
If not can I recompile the iptables/netfilter code to not change the destination address ? Where in the code I should do that ?

Thanks

[fast_ian]

...I want to modify the destination port of receiving packets according to the destination ip.

IIRC, you should be able to do this within the setup program on most routers;

Just tell it that anything coming in for XXX.XXX.X.XXX[optionally + port#] should really be forwarded wherever you tell it.

Cheers,
Ian

[ni_boy]

iptables can do it.

If you post your iptables rule it would help, I presume you are trying something like this

iptables -t nat -A PREROUTING -i eth0 -p tcp -s 1.2.3.4 -d 5.6.7.8 --dport 80 -j DNAT --to 5.6.7.8:8080

cheers

[idan72]

Hi,

I have 20000 servers on my machine so if I want to use nat I need to write 20000 line in iptable. Is this possible ?

I prefer to use the redirect option but the problem is that the destination address is modifing. Is there a way without modify the dest address using iptables or something else ?

Thanks

[ni_boy]

No. IPTables is not your solution, better code is.