Define the purpose of NIS
Define NIS terminology and daemons
Configure an NIS Master Server, NIS Slave Server and NIS Client
Distributed Environment Concerns
Common administrative concerns in a network environment are:
– Mainenance of separate copies of common configuration files for example, passwd, group, host
– Changes to a configuration file that must be propagated to all hosts on a network
– Probability of editing errors increase
How NIS Addresses Distributed Environment Concerns
NIS replaces replicated copies of common configuration files with one data map for each file and locates them on a central server
Enforces a consistent view of configurationfiles on a network
Simplifies administrative control of a network
NFS and /etc/passwd
Note: Make sure that UID numbers for users are identical on all machines.
NIS Centralized Control of /etc/passwd
+::0:0::: (Indicator to the kernel to go to the NIS server)
NIS Master Server-sys1
Master Server – Creates, maintains maps, Answers client requests
Slave Servers – Stores Copies of maps, Answers client requests
NIS Client – Requests and receives info from maps
NIS Domain Configuration
Each server and client is given a Domain Name in NIS.
When a client comes us it broadcasts over the network if there is any computer that can service its requests for that domain. The server or slave will respond.
NIS Master Server
/var/yp/accounting (yp stands for yellow pages)
Maintains the NIS Database Maps
Client Activity Client Server
——————— ————– —————–
login ypbind ypserv
change password yppasswd yppasswdd
Note: They rename the password command and then use a symbolic link from passwd to yppasswd.
1. Client sys3 – Broadcast need for server for accounting domain
2. Server sys1 – I’m available for accounting domain /var/yp/accounting
3. /var/yp/vingding/accounting.version – address of server
Note: There is a “ypset” command that allows you to bind to a specific host even if outside your local network.
ypwhich – displays what server you are bound to as an NIS server.
NIS Daemons Controlled by SRC
NIS Daemons and their Subsystems
File Path Subsystem GroupName
/usr/lib/netsvc/yp/ypserv ypserv yp
/usr/lib/netsvc/yp/ypbind ypbind yp
/usr/lib/netsvc/yp/rpc.yppasswdd yppasswdd yp
/usr/lib/netsvc/yp.rpc.ypupdated ypupdated yp
/usr/sbin/protmap portmap portmap
Note: If you are not running in a secure NFS invironment then make sure that the ypupdated daemon is not running.
Note: Also, the portmap daemon must be running.
System Default NIS Data Maps
/etc/passwd User names, user IDs, and passwords
/etc/group User groups
/etc/hosts Hostnames and IP addresses
/etc/aliases Aliases and mailing lists for the mail system
/etc/netgroup Netgroup definitions (used by NIS)
/etc/networks Network addresses
/etc/protocols Network protocol names and numbers
/etc/rpc Remote procedure call program numbers
/etc/services Network port numbers and service names
/etc/publickey Keys for Secure NIS
/etc/netid ID info for machine, hosts, and groups
1. NIS is a centralized database that simplifies system administration of common configuration files
2. Systems participating in an NIS environment belong to an NIS domain. A NIS domain is a group of systems that share the same named set of maps in a server’s /var/yp/
3. An NIS environment consists of one NIS master server, one or more NIS slave servers and multiple NIS clients
4. ypserv – is an NIS server daemon that handles NIS client requests
5. ypbind – is an NIS client daemon which is responsible for locating and binding to an NIS server
6. yppasswdd – is an NIS master server daemon that takes yppasswd change requests, updates the /etc/passwd source files and builds and transfers the new passwd map to the NIS slave servers.