Black Box 16 port User Manual page 230

A configuration file (if you specify one) contains general configuration parameters;
these parameters will have been created from another unit and saved to a file.
In the bootp response the minimum parameters to specify are :ht and :ha
There is no minimum number of parameters to specify in the bootfile or
configuration file; unspecified parameters will remain unchanged in the unit's
memory.
After processing the BOOTP response the unit will download additional files.If a
bootfile is specified, the unit will then download that bootfile (using tftp). If the bootfile
specifies other files e.g. a software file, the unit will compare that filename with the
filename in its memory; if it has changed the unit will then download that other file using
tftp. If the filename has not changed the unit will not download it.
Note In the bootp response you do not have to specify a bootfile. In the bootfile you do
not have to specify other files, such as the software file. If you wish, you can make
an entry in the bootptab file only.
Black Box Console Server user guide
230