NIS
Network Information Service (NIS) is a protocol developed by Sun to allow one to defer user authentication to a server. The server software is in the ypservAUR package, and the client software is in the yp-toolsAUR package. ypbind-mtAUR is also available, which is a multi threaded version of the client daemon.
Contents
NIS Server
Install Packages
Install the ypbind-mtAUR, ypservAUR, and yp-toolsAUR packages.
Configuration
/etc/hosts
Add your server's external (not 127.0.0.1) IP address to the hosts file. Make sure it is the first non-commented line in the file, yes, even above the localhost line, like so:
# # /etc/hosts: static lookup table for host names # #<ip-address> <hostname.domain.org> <hostname> #::1 localhost.localdomain localhost 192.168.1.10 nis_server.domain.com nis_server 127.0.0.1 localhost.localdomain localhost nis_server # End of file
This is due to a peculiarity in ypinit (maybe it's a bug, maybe it's a feature), which will always add the first line in /etc/hosts to the list of ypservers.
/etc/nisdomainname
Add the domain name to /etc/nisdomainname:
# NISDOMAINNAME="nis-domain-name"
/etc/ypserv.conf
Add rules to /etc/ypserv.conf for your your nis clients of this form:
# ip-address-of-client : nis-domain-name : rule : security
For example:
# 192.168. : home-domain : * : port
For more information see man ypserv.conf.
/var/yp/Makefile
Add or remove files you would like NIS to use to /var/yp/Makefile under the "all" rule.
Default:
# all: passwd group hosts rpc services netid protocols netgrp \ # shadow # publickey networks ethers bootparams printcap mail \ # # amd.home auto.master auto.home auto.local passwd.adjunct \ # # timezone locale netmasks
After that you have to build your NIS database:
# cd /var/yp # make
Or you can do it in a more automated fashion:
# /usr/lib/yp/ypinit -m
If you use this way you may skip manually adding lines to /var/yp/ypservers.
/var/yp/securenets
Add rules to /var/yp/securenets to restrict access:
# 255.255.0.0 192.168.0.0 # Gives access to anyone in 192.168.0.0/16
Be sure to comment out this line, as it gives access to anyone.
# 0.0.0.0 0.0.0.0
/var/yp/ypservers
Add your server to /var/yp/ypservers:
# your.nis.server
Set your domain name
# ypdomainname EXAMPLE.COM
Now edit the /etc/yp.conf file and add your ypserver or nis server.
ypserver nis_server
Start NIS Daemons
Start/enable the following systemd units:
-
rpcbind.service -
ypbind.service -
ypserv.service -
yppasswdd.service(to allow clients to change their password withpasswd)
NIS Client
Install Packages
The first step is to install the tools that you need. This provides the configuration files and general tools needed to use NIS.
# pacman -S yp-tools ypbind-mt
Configuration
Set your domain name
# ypdomainname EXAMPLE.COM
You can apply this permanently by editing /etc/nisdomainname and adding:
# NISDOMAINNAME="EXAMPLE.COM"
Now edit the /etc/yp.conf file and add your ypserver or nis server.
ypserver nis_server
/etc/hosts
It may be a good idea to add your NIS server to /etc/hosts
192.168.1.10 nis_server.domain.com nis_server
Start NIS Daemons
Start/enable the rpcbind.service and ypbind.service systemd units.
Early testing
To test the setup so far you can run the command yptest:
# yptest
If it works you will, among other things, see the contents of the NIS user database (which is printed in the same format as /etc/passwd).
/etc/nsswitch.conf
To actually use NIS to log in you have to edit /etc/nsswitch.conf. Modify the lines for passwd, group and shadow to read:
passwd: files nis group: files nis shadow: files nis
And then do not forget
# systemctl restart ypbind
/etc/pam.d/passwd
To allow a user on a client machine to change their password on the server, be sure that yppasswdd.service is started/enabled on the server.
Edit /etc/pam.d/passwd on the client to add the nis parameter to password/pam_unix.so:
password required pam_unix.so sha512 shadow nullok nis
See section 7 of The Linux NIS HOWTO for further information on configuring NIS clients.
Attention on Systemd V235 since 10/2017
Due a problem with sandboxing on systemd-logind, which deneys any IP connections from and to the systemd-logind service it may be nessesary to edit
IMHO, the best practical solution ist to override the system's default systemd-logind.service by a modified local version:
cp -a /usr/lib/systemd/system/systemd-logind.service /etc/systemd/system nano /etc/systemd/system/systemd-logind.service and comment out this line IPAddressDeny=any into # IPAddressDeny=any
This solution surrives an update of the systemd toolchain and keeps working after a reboot.
Workig, but not very recommended solution:
/usr/lib/systemd/system/systemd-logind.service and comment out this line IPAddressDeny=any into # IPAddressDeny=any
to make flawless login possible.
More resources
- The Linux NIS HOWTO,very helpful and generally applicable to Arch Linux.
- YoLinux NIS tutorial
- Quick HOWTO, Configuring NIS