NDBOOTD(8)						    BSD System Manager's Manual 						NDBOOTD(8)

NAME

     ndbootd -- Sun Network Disk (ND) Protocol server

SYNOPSIS

     ndbootd [-s boot2] [-i interface] [-w windowsize] [-d] boot1

DESCRIPTION

     ndbootd is a server which supports the Sun Network Disk (ND) Protocol.  This protocol was designed by Sun before they designed NFS.  ND sim-
     ply makes the raw blocks of a disk available to network clients.  Contrast this with the true namespace and file abstractions that NFS pro-
     vides.

     The only reason you're likely to encounter ND nowadays is if you have an old Sun 2 machine, like the 2/120 or 2/50.  The Sun 2 PROMs can only
     use ND to boot over the network.  (Later, the Sun 3 PROMs would use RARP and TFTP to boot over the network.)

     ndbootd is a very simple ND server that only supports client reads for booting.  It exports a disk that the clients consider to be /dev/ndp0
     (ND public unit zero).  The disk is available only to clients that are listed in /etc/ethers and have valid hostnames.  (Sun 2 PROMs don't do
     RARP, but they do learn their IP address from the first ND response they receive from the server.)

     boot1 is a file containing the mandatory first-stage network boot program, typically /usr/mdec/bootyy.  The layout of the exported disk is:

	   o   block 0: normally a Sun disklabel (but ignored by the PROM)

	   o   blocks 1-15: the first-stage network boot program

     With the -s boot2 option, ndbootd will also make a second-stage network boot program available to clients, typically /usr/mdec/netboot.  When
     boot2 is a filename, that file is the single second-stage network boot program to be served to all clients.

     When boot2 is a directory name, typically /tftpboot, ndbootd finds a client's second-stage network boot program by turning its IP address
     into a filename in that directory, in the same manner later Sun 3 PROMs do when TFTPing (i.e., if a client has IP address 192.168.1.10,
     ndbootd expects to find /tftpboot/C0A8010A.SUN2 ).

     When used in this last manner with an ND-aware first-stage boot program, ndbootd serves the same purpose in the Sun 2 netboot process as
     tftpd(8) serves in the Sun 3 netboot process.

     Any second-stage network boot program always begins at block 16 of the exported disk, regardless of the length of the first-stage network
     boot program.

     All first- and second-stage network boot programs must have all executable headers stripped off; they must be raw binary programs.

     The remaining options are:

     -i interface
		Only listen for ND clients on interface interface.  Normally ndbootd listens for clients on the first non-loopback IP interface
		that is up and running.

     -w windowsize
		This adjusts the window size of the ND protocol.  This is the number of 1-kilobyte packets that can be transmitted before waiting
		for an acknowledgement.  Defaults to 6.

     -d 	Run in debug mode.  Debugging output goes to standard error and the server will not fork.

FILES

     /etc/ethers
     /etc/hosts

SEE ALSO

     tftpd(8)

BUGS

     Whether or not there is a second-stage network boot program, the exported disk appears to all clients to have infinite length.  The content
     of all blocks not used by the first- or second-stage network boot programs is undefined.  All client reads of undefined blocks are silently
     allowed by the server.

BSD
								    May 9, 2001 							       BSD