i want to redirect incoming packets to another and another host that packets redirects to change destination of packets and send them back to the sender!like load balancers with DSR.
we have 3 Computer.computer1 send a tcp packet to computer 2 with source 1 and destination 2.computer 2 send received packet with source 1 and destination 3 to computer3.and computer3 send packets to computer1 with source 3 and destination 1.i used netfilter to get packets and change mac and ip and send them with dev_queue_xmit but packets drop in hub/switch.is better way to do this with modules?!
or source code to see?

iptables is what you want to be looking at. Do a Google search, you should be able to find what you're looking for.

http://www.youtube.com/watch?v=WL1foQKD3OI
(Sorry, had to be said.... I'm not the only one who is confused by that sentence)

i'm so so sorry about my english!
i know what iptable is.but i want to write module.
in fact i want to implement an load balancer(one-armed , direct server return "DSR",layer 2 or 3) with netfilter(just for packet capturing in layer 2 of tcp/ip,PREROUTING).
1 - i got packets
2 - i changed destination ip and mac to ip and mac of server
3 - i sent it with dev_queue_xmit and this function return 0(successful)
but no packet receive on server!!!

You don't need to write your own module to do load balancing.

Here are a couple of pages with information about it:
Using nth module: http://linuxgazette.net/108/odonovan.html
Using clusterip module: http://lserinol.blogspot.com/2008/05...-iptables.html (this implements LB on the servers themselves, without the need for a dedicated load-balancer box)

You can also use LD or keepalived:
http://www.ultramonkey.org/3/topologies/lb-eg.html
http://www.howtoforge.com/high-avail...ed-debian-etch
http://billboebel.typepad.com/blog/2...alancing_.html

---------- Post added 12th Oct 2011 at 09:11 ----------

You don't need to write your own module to do load balancing.

Here are a couple of pages with information about it:
Using nth module: http://linuxgazette.net/108/odonovan.html
Using clusterip module: http://lserinol.blogspot.com/2008/05...-iptables.html (this implements LB on the servers themselves, without the need for a dedicated load-balancer box)

You can also use LD or keepalived:
http://www.ultramonkey.org/3/topologies/lb-eg.html
http://www.howtoforge.com/high-avail...ed-debian-etch
http://billboebel.typepad.com/blog/2...alancing_.html

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ThankYou ThankYou ThankYou.
Every one who helped me .