Sepherosa Ziehau’s added TSO support (that’s TCP Segmentation Offloading”, or “Large Segment Offload” going by Wikipedia) within IPv4 on DragonFly, pushing segmentation work from the CPU to the network card.  There’s also some DragonFly-specific improvements.

There’s been a lot of commits from him lately focused around network card improvements; they haven’t been easily summarizable, but it’s worth watching if you are interested in high-bandwidth usage and the hardware to support it.