base# ls -l ip*
crw------- 1 root wheel 29, 0 May 14 16:45 ipl
crw------- 1 root wheel 29, 1 May 14 16:45 ipnat
crw------- 1 root wheel 29, 2 May 14 16:45 ipstate
from sys/arch/i386/i386/conf.c:
cdev_ipf_init(NIPFILTER,ipl), /* 44: ip-filter device */
which looks like ip-filter has major 44, not 29.
.mrg.