how could a packet size can be 2846 bytes ?

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Hi There , As per the suggested post ,when Packets are going out then there will be segmentation offloading , but what if incoming packet size is also greater than 1518 e.g. https://drive.google.com/open?id=1OnB... Here is my wireshark capture where I have received packet(packet no. 441) from google server. The packet size here is 2762. Please also suggest how to calculate TCP checksum for such a large packet because normal method of calculating checksum with (pseudo header+tcp header +tcp data ) is giving me wrong answer here.Is there any additional condition for large packet while calculating checksum. Thanks in advance.....

but what if incoming packet size is also greater than 1518

To quote Christian_R:

For receiving packets the parameter is called Receive Side Coalescing.

Is there any additional condition for large packet while calculating checksum.

Yes. The additional condition is "you have to figure out what the original TCP segments were that the segmentation offloading, or receive-side coalescing, combined, and reconstruct them, complete with their IP headers and TCP headers, and calculate the TCP checksums of those packets".

This is probably impossible.

Hey Thanks ,Now I understand the 'Receive Side Coalescing' concept as well. I have one more query ,If I wanna send packet of size greater than 1518 bytes then will I be calculating checksum(sending packet via raw sockets) over entire packet and then let my NIC handle segmentation offloading and checksum recalculation for me ?Or my calculated checksum doesn't matter at all and NIC will ignore my checksum and do stuff by its own.

here is a nice doc about segmentation offloading https://docs.microsoft.com/en-us/wind...