[VPN] help regarding vpn client

[tictac toe]

hi 

i did like to know if someone could help me with
writing a vpn client over mobile ip.
if not the mobile ip, i looking for help to write just
a vpn client. I know the steps from IKE, IPSec to
replay protection but i don't exactly understand how i
can modify the same packet while performing the each
step. 

regards


	
	
		
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