Disabling Jumbo frames is not a good solution - yes it works, but it will break again soon with someone else’s windows box. Thats where I was heading with your traces seeing if your DF (Dont fragment) bit was set in Windows – Windows used to have bad bad issues trying to detect a path MTU (PTMUD) which always set the DF bit to True on PMTUD failure causing larger frames to be discarded when they needed to be fragmented at the next hop layer 3 boundary.
You just need to query the MTU of the Windows Driver Interface to detect Jumbo or not. Anything > 1500 is Jumbo (Usually its 9000 mtu for Jumbo)
Here are the easy steps I took to do it in Windows 10 .
- Open a command prompt as administrator. ( …
- type the command : netsh interface ipv4 show subinterfaces.
- This should output your interfaces and current MTU size.