> Anyone see what I'm doing wrong?

have you tried "hd="?

The bootfile name is limited to 64 characters, and what you have is
well within the limits, so that doesn't make sense.   I would try:

vax.home.net:\
    :ht=ethernet:\
    :ha=08002b0e44f5:\
    :sm=255.255.255.0:\
    :lg=192.168.1.16:\
    :ip=192.168.1.6:\
    :hd=:\
    :hn:\
    :bs=auto:\
    :bf=/usr/export/vax/root/netbsd:\
    :rp=/usr/export/vax/root/:

			       _MelloN_