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

From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Tue, 29 May 2007 10:55:55 -0700
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.