I recently upgraded my home desktop and shortly afterwards noticed problems transferring large files to/from the Internet and even across my home Local Area Network (LAN).
It appeared to me that I was suffering from a auto-negotiation and duplex mis-match between my new desktop and my legacy un-managed Netgear GS608. The Gigabyte GA-Z77X-UD5H motherboard in my new desktop includes an Intel(R) 82579V Gigabit NIC along with a Qualcomm Atheros AR8161/8165 Gigabit PCI-E NIC. I was using the Intel 82579V Gigabit NIC to connect to the Netgear GS608. I’m my older desktop I was using a Realtek PCI-E Gigabit NIC which was built into the Gigabyte EP45-UD3P motherboard.
I went down to my local Best Buy and purchased a replacement GS608 hoping that 1) the legacy was ‘defective’ in some way or 2) a later version of the GS608 would work with Intel 82579V NIC my new desktop.
It turned out that the later was true and the GS608 v3 worked fine with my new desktop where as the my original GS608 v2 had all sorts of auto-negotiation issues with the Intel 82579V NIC.