Re: why not enable tcp_pmtud_blackhole_detect in default

2018-03-08 Thread Cui, Cheng
Kevin, Thanks for the reply. I think you have answered most of my doubts. But I would like to be clear that, is there a very strong reason why you run this in production even it often causes unnecessary lower MSS with lower performance? Thanks, Cheng Cui On 3/7/18, 3:35 PM, "Kevin Bowling" w

Re: why not enable tcp_pmtud_blackhole_detect in default

2018-03-07 Thread Kevin Bowling
Cheng, We run this in production at Limelight Networks (i.e toward a broad spectrum of Internet hosts) and must to deal with some uncommon network topology. There are currently some limitations as you point out. Like you say the signaling is not perfect and we do often clamp MSS unnecessarily. T

why not enable tcp_pmtud_blackhole_detect in default

2018-03-07 Thread Cui, Cheng
Dear all, Reading through the tcp blackhole detection code (support RFC 4821) in FreeBSD including the recent bug fixes, I am wondering why is it still not enabled in default? Given the fact that this implementation was a merge from xnu, and the xnu has enabled it in default, do we have a plan