SOMAXCONN (kern.somaxconn), SOMINCONN (kern.sominconn), and TCPTV_KEEP_INIT
(net.inet.tcp.keepinittime). when this is not enough (ie. overfull), start
doing tail drop, but slightly prefer the same port.
make netinet work on systems where pointers and longs are 64 bits
(like the alpha). Biggest problem: IP headers were overlayed with
structure which included pointers, and which therefore didn't overlay
properly on 64-bit machines. Solution: instead of threading pointers
through IP header overlays, add a "queue element" structure to do
the threading, and point it at the ip headers.
