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From: frank@croton.nyo.dec.com (Frank Wortner)
Newsgroups: comp.sys.dec
Subject: Re: Internet address help needed
Message-ID: <2223@riscy.enet.dec.com>
Date: 9 May 91 13:45:09 GMT
References: <1991May7.231307.3466@uoft02.utoledo.edu>
Sender: news@riscy.enet.dec.com
Reply-To: frank@croton.nyo.dec.com
Organization: NY ULTRIX Resource Center, Digital Equipment Corporation
Lines: 39

In article <1991May7.231307.3466@uoft02.utoledo.edu>, fax0236@uoft02.utoledo.edu writes:

|>Help!  We just got our DECstation 3100s on the internet, and are trying
|>to change their internet addresses.  For some reason, even though we
|>have changed the /etc/hosts file and rebooted, the diskless workstations
|>(booting off a DECsystem 3100 server) keep coming up with their old
|>address and therefore won't reboot.

Diskless ULTRIX workstations get their IP addresses from an object file that is
downloaded into them at boot time.   If you do a

	getnode DISKLESS

replacing the DISKLESS with the name of the client, you'll see the three files are
downloaded at boot time.   Two are kind of obvious:  a bootstrap loader called
netload, and vmunix.  The third is a file called netblk.o.  This contains information
that the client requires to boot itself:  its IP address, its server's name and IP address,
its swap file location, etc.  This file is located in the client's root area /etc directory
(/dlclient0/DISKLESS.root/etc/netblk.o).

You might think that there is a corresponding netblk.c, and, lo, there is.  ;-)  It's
usually in /dlclient0/DISKLESS.root/etc/netblk.c.  You can edit this file, change the
IP address in the file, recompile

	cc -c netblk.c

and try a reboot.

BTW, the IP address in that file might not be obvious --- look in the include file
/usr/include/sas/mop.h to figure out which number it is.

Finally, I don't guarrantee that this will work.  The right way is to delete the client
area and make a new one, but I have done what I just described successfully.  Just
please be aware that this technique is my own and is not endorsed by
Digital.

Good luck!

					Frank