Hi, I just upgraded FreeBSD 5.3-STABLE/AMD64 successfully to FreeBSD 6.0-STABLE/AMD64. I was using debug.mpsafenet=0 and net.inet.tcp.sack.enable=0 with 5.3/AMD64 due to TCP SACK/MPSAFENET bug. Is it safe to enable these in 6.0 now? thanks, Ganbold I didn't put yet additional 4GB RAM. I will try it later.