Slackware-NIS-mini-HOWTO
How to set up a NIS server and configure NIS clients on Slackware Linux
14-Dec-2000
David Cantrell <david@slackware.com


==============
THE NIS SERVER
==============

STEP 1:  Decide which machine will be the NIS server
----------------------------------------------------

This is usually not a very involving process, but does require some
thought.  You'll want to use a machine that is on most of the time and
does not need to reboot into other operating systems.  If you have an
existing fileserver, that would be a good choice for your NIS server.


STEP 2:  Decide on what you want NIS to serve
---------------------------------------------

NIS is fairly complex.  It allows you to distribute all kinds of
information.  Things like usernames, passwords, groups, hostnames, and
network services that should be running.  The most common use is to use
NIS as a common user logon authetication system.  The second most common
use is to have it share NFS automount maps so that users logging in on a
system will have their home directory automounted for them.

In this mini-HOWTO, I will explain how to set up your NIS server and
clients for passwd/group sharing and home directory sharing.


STEP 3:  Move home directories to sharing location
--------------------------------------------------

In order to make the home directory NFS shares work seamlessly across the
NIS server and clients, I move them to /export/home.  This is the location
they will be mounted on the client, so I make them exist there on the
server as well.  You might not have /export on your server, so let's make
it:

   mkdir -p /export

Now make the home directory location:

   mkdir /export/home

Now move all your home directories over to /export/home.  You should leave
"ftp" in /home, as that's where Slackware installs it and it is sometimes
site specific.  These commands should move all home directories to
/export/home and leave ftp in /home:

   mv /home/* /export/home
   mv /export/home/ftp /home


STEP 4:  Edit home directory paths on the server
------------------------------------------------

Since home directories are now in /export/home, you need to edit
/etc/passwd on the server to reflect those locations.  If you have a user
called "david", you will want to change his home directory to
/export/home/david.  Do this for all users on the system.


STEP 5:  Write the automount maps
---------------------------------

I usually make two automount maps for the home directories.  One is called
auto.master and controls how the automounter works.  The other is called
auto.export and will describe the /export map.

Edit /etc/auto.master and add this to it:


   #
   # auto.master - Master map file for NFS automounter
   #
 
   /export auto.export --timeout 60


Now edit /etc/auto.export and add this to it:


   #
   # auto.export - NFS automounter configuration file
   #
 
   # Home directories
   home -fstype=nfs <NFS/NIS server>:/export/home


Of course, replace <NFS/NIS server> with the hostname of your NFS/NIS
server.


STEP 6:  Edit the NFS exports file on the server
------------------------------------------------

Now we need to make sure that /export is shared from the server.  Edit
/etc/exports and make sure this line is present:


   /export (rw,no_root_squash)


Save the file and restart the NFS server daemons:

   killall -HUP rpc.nfsd rpc.mountd


STEP 7:  Pick a name for your NIS domain
----------------------------------------

Each NIS domain needs to have a unique name.  Do not use the same name as
your DNS domain.  This should be something different.  I will use "mynis"
in this example.

Edit /etc/defaultdomain and add the name of your NIS domain:


   mynis


Save and exit.  The name of your NIS domain shoulw be the only thing in
that file.  Once you've done that, set the NIS domain with this command:

   nisdomainname `cat /etc/defaultdomain`


STEP 8:  Edit /var/yp/Makefile
------------------------------

The NIS server has a Makefile that controls what maps are served out by
NIS.  Each time you make a change (such as adding a user), you should go
into /var/yp and type "make" to update the NIS information.

In this file we need to edit the all: target and specify the stuff we want
to share.  Here's what your all: target should look like:

   all: passwd group hosts rpc services netid protocols netgrp mail \
        shadow auto.master auto.export

Now find the line that looks like this:

   AUTO_LOCAL  = $(YPSRCDIR)/auto.local

We want to add this line just after that line:

   AUTO_EXPORT = $(YPSRCDIR)/auto.export

Now find the auto.local: target.  We need to add this target just after
that target:

   auto.export: $(AUTO_EXPORT) $(YPDIR)/Makefile
   	@echo "Updating $@..."
      -@sed -e "/^#/d" -e s/#.*$$// $(AUTO_EXPORT) | $(DBLOAD) \
      		-i $(AUTO_EXPORT) -o $(YPMAPDIR)/$@ - $@
      -@$(NOPUSH) || $(YPPUSH) -d $(DOMAIN) $@

Save the Makefile and exit.


STEP 9:  Edit /var/yp/securenets
--------------------------------

Edit /var/yp/securenets and change the "0.0.0.0   0.0.0.0" line to
something like this:

   255.255.255.0   192.168.1.0

You should specify your network address and submask there, this is only 
an example.  This example restricts NIS access to any machine on the
192.168.1 class C subnet.


STEP 10:  Create an /etc/ypserv.conf file
-----------------------------------------

The only line you need in this file is:

   dns: yes

This line tells ypserv to resolve hostnames using a DNS server instead of
relying on NIS hostname maps (which you probably aren't using).  Save and
exit.


STEP 11:  Start ypbind
----------------------

Start ypbind:

   /usr/sbin/ypbind

Use ps to make sure it started and is running properly.  You will probably
see a master and slave process for it.


STEP 12:  Start ypserv
----------------------

Start ypserv:

   /usr/sbin/ypserv

Use ps to make sure it started and is running properly.


STEP 13:  Initialize the NIS maps
---------------------------------

We need to initialize the NIS maps with this command:

   /usr/lib/yp/ypinit -m

Fill in the blanks for all machines on your network that will be acting as
NIS servers.  At this point, you probably want to fire up rpc.yppasswdd to
make sure that users on NIS clients can run chfn and passwd.


STEP 14:  Done, making sure NIS stuff loads at bootup
-----------------------------------------------------

Your NIS server is now up and running.  You should edit /etc/rc.d/rc.inet2
and make sure the following block is uncommented:

   # Setting up NIS:
   # (NOTE: For detailed information about setting up NIS, see the documentation
   # in /usr/doc/yp-tools, /usr/doc/ypbind, and /usr/doc/ypserv)
   #
   # First, we must set the NIS domainname.  NOTE: this is not
   # necessarily the same as your DNS domainname, set in
   # /etc/resolv.conf!  The NIS domainname is the name of a domain
   # served by your NIS server.

   if [ -r /etc/defaultdomain ]; then
     nisdomainname `cat /etc/defaultdomain`
   fi

   # Then, we start up ypbind.  It will use broadcast to find a server.

   if [ -d /var/yp ] ; then
     echo -n " ypbind"
     ${NET}/ypbind
   fi

   # If you are the NIS master server for the NIS domain, then
   # you must run rpc.yppasswdd, which is the RPC server that
   # lets users change their passwords.
   
   if [ -x ${NET}/rpc.yppasswdd ]; then
     echo -n " yppasswdd"
     ${NET}/rpc.yppasswdd
   fi

It's probably adviseable to run rpc.yppasswdd with this line:

   ${NET}/rpc.yppasswdd -e chsh -e chfn

This ensures that chfn and chsh work.  You also need to add this after the
ypbind if block:

   if [ -x ${NET}/ypserv ]; then
     echo -n " ypserv"
     ${NET}/ypserv
   fi

The ypserv program needs to run on the NIS server.



==============
THE NIS CLIENT
==============

STEP 1:  Set the NIS domain
---------------------------

Edit /etc/defaultdomain just like you did on the server and enter the name
of your NIS domain.


STEP 2:  Edit /etc/yp.conf
--------------------------

Open /etc/yp.conf in a text editor and make sure this line is present:

   ypserver <IP or hostname of the NIS server>

Specify either the IP address or hostname of your NIS server.  If you
don't have working hostnames, you must use the IP address here.


STEP 3:  Set the NIS domain
---------------------------

Set the NIS domain by typing this command:

   nisdomainname `cat /etc/defaultdomain`


STEP 4:  Run ypbind
-------------------

Start ypbind with this command:

   /usr/sbin/ypbind


STEP 5:  Test the NIS connection
--------------------------------

See if the NIS server is working with this command:

   ypcat passwd.byname

If you see the /etc/passwd entries from the NIS server, you're good to go.
Otherwise, go back to the NIS server section and see if you missed any
steps.


STEP 6:  Edit /etc/nsswitch.conf
--------------------------------

You need to edit /etc/nsswitch.conf and tell it to use NIS for passwd,
shadow, and group.  Change those entries to:

   db files nis

Change the automount entry to:

   files nis


STEP 7:  Enable NIS logins in /etc/passwd and /etc/group
--------------------------------------------------------

Edit /etc/passwd and add this line to the end:

   +:::::

Edit /etc/group and add this line to the end:

   +:::


STEP 8:  Create the /export directory for home directory mounting
-----------------------------------------------------------------

Make sure you have that directory:

   mkdir -p /export


STEP 9:  Create an rc.autofs script
-----------------------------------

The included rc.autofs script should be moved into /etc/rc.d.  Edit
rc.local and add this line:

   /etc/rc.d/rc.autofs


STEP 10:  Done, enable NIS stuff at bootup
------------------------------------------

Your NIS client is now configured.  Edit /etc/rc.d/rc.inet2 and uncomment
this block:

   # Setting up NIS:
   # (NOTE: For detailed information about setting up NIS, see the documentation
   # in /usr/doc/yp-tools, /usr/doc/ypbind, and /usr/doc/ypserv)
   #
   # First, we must set the NIS domainname.  NOTE: this is not
   # necessarily the same as your DNS domainname, set in
   # /etc/resolv.conf!  The NIS domainname is the name of a domain
   # served by your NIS server.

   if [ -r /etc/defaultdomain ]; then
     nisdomainname `cat /etc/defaultdomain`
   fi

   # Then, we start up ypbind.  It will use broadcast to find a server.

   if [ -d /var/yp ] ; then
     echo -n " ypbind"
     ${NET}/ypbind
   fi