Hi all, I am not very sure if this is the right mailing list to post this question . Point me to correct one if this is wrong .. I am trying to implement Fault tolerant TCP as explained in http://citeseer.ist.psu.edu/alvisi00wrapping.html While looking for some information regarding how to implement this , i came across netfilter framework. I am new to linux world so i would like to have some help about this before i proceed. The idea in paper is to implement a kernel module which will intercept all the packets coming to server tcp and log them to stable buffer.If server crashes , then replay these logs. Also to handle client connection correctly ,it intercepts all outgoing packets and modifies the sequence number and thus the "segment" depending upon the packet's state in stable buffer( i.e. commited /no ). So i was wondering ,is netfilter the right choice to about it ?? or does it intercept packet below IP layer (in PRE_ROUTING) ?? Is thr a way to sit between TCP and IP protocol implementation and intercept all the communication between them ?? What is the other way to achieve this if not netfilter framework ?? Any help in this regard is highly appreciated ... Regards, TellMeMore