I got frustrated when trying to upload objects into thingiverse and it kept failing. Furthermore the speed was horrible by about 7kbps and it dropped.
Reason being was that there's an option called Large Send Offload (IPv4) enabled on my NIC's "advanced" tab.
After disabling this option, I got full speed by about 50kbps speed and successfully uploaded my object. Source are here and I don't recall enabling them in the past. Further reading about LSO are here