MTU

I have been updating this blog post over the years since I first discovered the issue with my computer in Windows Vista, now I am on Windows 8 and also on |FTTC broadband; |Path MTU Discovery seems to just work. I have tested the process so the approach and the commands still work in Windows 8, I however no longer need to use this process personally. For some reason that has escaped me |Path MTU Discovery (PMTUD) in Windows just doesn’t seem to figure out the MTU for a given path (something to do with routers being poorly configured to not respond to ICMP requests). So Windows uses the default. For the most part this doesn’t affect anyone, however if it does affect you, it really annoys you. Failure of PMTUD will result in some websites not loading correctly, having trouble connecting to normally reliable online services and general Internet weirdness. The resolution is to set your default MTU to one lower than the Ethernet default of 1500. Here is how: ...