-.Sh KERNEL OPTIONS
-The following options in the kernel configuration file are related to
-.Nm
-operation:
-.Bd -literal
- IPFIREWALL - enable ipfirewall (required for dummynet).
- IPFIREWALL_VERBOSE - enable firewall output.
- IPFIREWALL_VERBOSE_LIMIT - limit firewall output.
- DUMMYNET - enable dummynet operation.
- NMBCLUSTERS - set the amount of network packet buffers
- HZ - sets the timer granularity
-.Ed
-.Pp
-Generally, the following options are required:
-.Bd -literal
- options IPFIREWALL
- options DUMMYNET
- options HZ=1000 # strongly recommended
-.Ed
-.Pp
-additionally, one may want to increase the number
-of mbuf clusters (used to store network packets) according to the
-sum of the bandwidth-delay products and queue sizes of all configured
-pipes.