Description of Problem:

In network_support.c: build_bootp_record() (used when using static addrs, NOT
bootp/dhcp) contains:

    for (i = 0;  i < bp->bp_hlen;  i++) {
        bp->bp_chaddr[i] = 0xFF;
    }

which has confused people because it causes the displayed ESA address (displayed
by show_bootp) to be all Fs, which worries some people. Instead it should fetch
the real ESA using ioctl(s, SIOCGIFHWADDR, &ifr) like in
boot_support.c:do_bootp()