Wireshark · Wireshark-users: Re: [Wireshark-users] Verifying TCP segmentation Offloading

[Guy Harris <guy@xxxxxxxxxxxx>]

SUDESH TENDULKAR wrote:
> I want to verify whether TCP segmentation Offloading is actually happening .
> Can i use wireshark (with some options) so that i can capture packets 
> before those entering NIC ?

"entering NIC" in what sense?

> so that i can see large TCP Payload (>1500 
> bytes) entering NIC ?

OK, you mean it in the sense of packets being passed to the NIC from the 
host, rather than being received from the network by the NIC.

That depends on how the OS handles packets being sent.  There are no 
options to Wireshark to control this.  All I can suggest is either

	1) asking the supplier of the OS what an application using libpcap will 
see in this case (or, if it's an open-source OS, getting the source and 
figuring it out yourself)

or

	2) trying it yourself.