I don't know much about it, but it's briefly described here: https://www.intel.com/content/www/us/en/support/network-and-i-o/ethernet-products/000005593.html ht

I don't know much about it, but it's briefly described here: https://www.intel.com/content/www/us/en/support/network-and-i-o/ethernet-products/000005593.html https://www.intel.com/content/www/us/en/support/network-and-... (ctrl-f offload) https://wiki.linuxfoundation.org/networking/toe https://wiki.linuxfoundation.org/networking/toe suggests it's done mostly in closed-source firmware.