CORRECT TEXT
Download ftp://192.168.0.254/pub/boot.iso to /root, and mounted automatically under /media/cdrom and which take effect automatically at boot-start.
Answer: see explanation below.
Explanation
# cd /root; wget ftp://192.168.0.254/pub/boot.iso
# mkdir -p /media/cdrom
# vim /etc/fstab
/root/boot.iso /media/cdrom iso9660 defaults,loop 0 0
# mount -a
mount [-t vfstype] [-o options] device dir