In the hope of increasing networking performance, I’ve set the following sysctls in /etc/sysctl.conf;

# Increase send/receive buffer maximums from 256KB to 16MB.
# FreeBSD 7.x and later will auto-tune the size, but only up to the max.
net.inet.tcp.sendbuf_max=16777216
net.inet.tcp.recvbuf_max=16777216

# Double send/receive TCP datagram memory allocation.  This defines the
# amount of memory taken up by default *per socket*.
net.inet.tcp.sendspace=65536
net.inet.tcp.recvspace=131072

# Enlarge buffers for BPF device.
sysctl net.bpf.bufsize=65536
sysctl net.bpf.maxbufsize=524288