CIS 192B – Lesson 3 Network Information Services

CIS 192B – Lesson 3 Types of Services Infrastructure –DHCP, DNS, NIS, AD, TIME Intranet –SSH, NFS, SAMBA Internet –MAIL, WEB, FTP, CUPS

CIS 192B – Lesson 3 Components of a Service / etcusr var sysconfig init.dbin lib sbin log

CIS 192B – Lesson 3 How To Change a Hostname Use the hostname command to change the name in RAM Edit /etc/sysconfig/network to make the change permanent. (Note: some Linux systems use the file /etc/hostname) Update the /etc/hosts file to use the new name with the loopback entry. (Note: this is very important for sendmail.)

CIS 192B – Lesson 3 Components of NIS The ypserv package contains the server daemon and its configuration file. The ypbind package contains the client daemon and its configuration file. The yp-tools package has several client utilities: ypcat - dumps the content of a particular NIS map file. ypwhich - specifies the name of the NIS server you are using. ypmatch - like ypcat, but returns only specific key values yppasswd - allows the user to change their password on the NIS server NIS is from Sun Microsystems and is designed around the Remote Procedure Call API and utilizes the portmap daemon for its operation. It was formerly called "Yellow Pages“ – thus the “yp” prefix

CIS 192B – Lesson 3 Server Side NIS /etc/ypserv.conf file syntax: option: # This is an option line host : domain : map : security # This is an access rule Host Specifiers –hostname –IP address –network addresses Security –none –port –deny ypserv - serves the map files for clients in the domain ypinit - creates the map files yppasswdd - allows clients to change passwords on the server

CIS 192B – Lesson 3 The NIS Clients Verify that portmap is running and that the firewall is allowing both udp and tcp packets from the server. Setup the NIS domain name –Run the command domainname name –Set the variable NISDOMAIN=doimainname in the /etc/sysconfig/network file. Configue the yp.conf file using one of three syntaxes: –domain NISDOMAIN server HOSTNAME –domain NISDOMAIN broadcast –ypserver HOSTNAME Edit the /etc/nsswitch.conf file and add nis to the appropriate services. Start the ypbind service. Clients need to run a daemon as well since accessing files like /etc/passwd and /etc/hosts is a common and continual process.

CIS 192B – Lesson 3 Project Diagram 1 Roter Router/Firewall Roter /24 NoPar Internet X.0/24 DNS DHCP NFS Mail CUPS SSH Server1 Server2 Client1

CIS 192B – Lesson 3 Project Diagram 2 Roter Router/Firewall NoPar / X.0/ Y.0/24 Roter ClientServer NFS SSH DHCP Server Mail DNS Server HTTP FTP Internet

CIS 192B – Lesson 3 Project Diagram 3 Roter Router/Firewall NoPar /24 Internet Roter Router/Firewall Roter Server CUPS DNS Roter Server1 DHCP NFS Roter Server2 SSH DNS