>        note also freebsd and Solaris do randomize ip_id.
>http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/ip_output.c.diff?r1=1.188&r2=1.189


For those who have poor reading skills, please note that the FreeBSD 4
randomized ip_ids are an config-time option, and the option defaults
to "off".  I think that's a *good* example for us to follow.

(Anyone who read the netipsec/ code should have notice that; netipsec/
still has support for the FreeBSD 4 option header and ifdef.)