Hi, On 2016-06-16, at 23:09, Andrey Vagin wrote: > I can't reproduce this issue, now I'm trying to understand why it works > for me and doesn't work for you. just to conclude this thread for the list: Andrey and me debugged this off-list. The issue arose, because my code did a bind() to 0.0.0.0 in TCP_REPAIR mode. When turning off TCP_REPAIR and sending into the socket, this caused minimum-MSS-sized segments to be transmitted. The issue goes away when I bind() to the local IP address of my local egress interface. To me at least, this is a POLA violation (excuse the FreeBSD terminology :-) Either binding to 0.0.0.0 should fail, or it should succeed and full-sized segments should be sent. But at least I have a work-around now. Thanks, Lars