I am student graduating in Indian Institute of Technology, India. I have a small problem regarding IP tables. "DOes the kernel recalculates the checksum field in the packet after SNAT or DNAT. If yes , does the kernel calculates the checksum right from the scratch or does it just change the checksum due to SNAT or DNAT." "I am changing the answer section of a dns reply packet captured at the firewall( this updated reply is to be forwarded through SNAT), will the kernel recompute the new valid checksum for both IP and UDP headers or not." "If no what should i do to correct the checksum because the packet gets dropped at the client side. " "Can UDP checksum be disabled at the client side by zeroing the checksum field in UDP header." Thanking You regards raman mittal Indian Institute of Information Technology
