Sonic.net

I had Comcast Internet and all my host tested roughly same down and up load speeds = > 200/12 mbps

I switched Ethernet cable from my ASUS RT-AC87R router to fiber optical network Sonic and all hosts are much slower except one ubuntu 16.04 which runs ~900/100, but similar box also ubuntu only does ~100/100, upload almost the same.

This seems to be either with my router or Sonic provide (need to retest)

Any help is appreciated.

That "~100/100" would clearly suggest a 100BaseT link.

I optimized setting and getting full speed on ubuntu boxes, still ~30% on Windows.

On Comcast I used to get full speed on IPv6 and similar low speed on Windows. Anybody see the same?