Linux Administration

Linux Administration : 

Linux Administration By: - Amit Pramanik Bishal Ghosh Souvik Kolay RCCIIT

Basic about Linux : 

What is Linux ? -Linux is an open source, freely distributable Unix like operating system that uses Linux kernel . What is Kernel ? - Kernel is the program acting as chief of operations. Is Linux Free? -Yes, Linux is one of the most prominent examples of free and open source software collaboration. Basic about Linux

Installation of Linux : 

Installation of Linux Methods of installing Linux: FTP:-This is one of the earliest methods for performing network installations. HTTP:-The installation tree is served from a web server. NFS:-The distribution tree is shared/exported on an NFS server. SMB:- This method is relatively new, and not all distributions support it. The installation tree can be shared on a Samba server or shared from a Windows box. From the Optical Media

Slide 4: 

Username Field : Password Field : User-ID Field (UID): Group-ID Field (GID): GECOS: Directory: Shell: Managing User Account

Slide 5: 

Under Linux, every file and program must be owned by a user. Each user has a unique identifier called a user ID (UID). Each user must also belong to at least one group, a collection of users established by the system administrator. Users may belong to multiple groups. Like users, groups also have unique identifiers, called group IDs (GIDs). The /etc/passwd file stores the user’s login, encrypted password entry, UID, default GID, name (sometimes called GECOS), home directory, and login shell. Managing User Account

File System of Linux : 

File System of Linux A file system is a data structure which interprets the physical sector of a disc into logical directory structure. The logical structure will help computers and users to trace files. The file system registers the location of the files and directories on the disc .

Network Configuration : 

Network Configuration The ifconfig program is primarily responsible for setting up network interface cards (NICs). All of its operations can only be performed through command-line options, as its native format has no menus or graphical interface. Multiple IP address can be assigned for single NIC. Network configuration file stores in /etc/sysconfig/network-scripts/ifcfg Global Parameter configuration file stores in /etc/sysconfig/network.

Network Configuration File : 

Network Configuration File DEVICE=eth1 BOOTPROTO=none HWADDR=00:12:79:9E:DC:0B ONBOOT=yes TYPE=Ethernet DHCP_HOSTNAME=rcciit.com USERCTL=no PEERDNS=yes IPV6INIT=no IPADDR=192.168.250.24 NETMASK=255.255.255.0 GATEWAY=192.168.250.21

DHCP : 

DHCP DHCP provides a method for hosts on a network to request, and be granted, configuration information including the addresses of router and nameservers. DHCP forwarding agents allow clients to receive addresses from a server which is not located on the same network segment. IP addresses are either dynamically assigned from a range or pool of addresses or statically assigned by MAC address.

Service Profile: DHCP : 

Service Profile: DHCP Packages: dhcp Daemons: dhcpd Script: dhcpd Ports: 67(bootps), 68(bootpc) Configuration: /etc/dhcpd.conf /var/lib/dhcp/dhcpd.leases Related: dhclient Sample configuration provided under : /usr/share/doc/dhcp - <version>

DHCP Configuration File : 

DHCP Configuration File global definitions ddns-update-style none; # turn off DDNS updates option domain-name “example.com” ; # domain name given to client option domain-name-servers 192.168.1.254; default-lease-time 21600; # seconds till expire max-lease-time 43200; # maximum lease time subnet 192.168.10.0 netmask 255.255.255.0 { option routers 192.168.10.20; # local gateway option subnet-mask 255.255.255.0; # local subnet mask # Range configuration DHCP range 192.168.10.21 192.168.10.100; # static configuration for each host BOOTP host station1 { hardware ethernet 00:a0:cc:3d:0b:39; fixed-address 192.168.10.39; } }

FTP : 

FTP FTP configuration file stores in /etc/vsftpd/vsftpd.conf Default User(Anonymous) can access only /var/ftpG Generally used to transfer single with proper authentication from previously configured sender’s folder to reciver’s folder

FTP Configuration File : 

FTP Configuration File anonymous_enable=YES anon_upload_enable=YES /etc/vsftpd/ftpusers ==> denied access /etc/vsftpd/user_list ==> userlist_enable=YES userlist_deny=YES/NO

Telnet : 

Telnet Telnet is a network protocol used on the Internet or local area networks to provide a bidirectional interactive text-oriented communications facility using a virtual terminal connection. User data is interspersed in-band with Telnet control information in an 8-bit byte oriented data connection over the Transmission Control Protocol (TCP). Telnet can not restrict a user after connection to the host has made, (i.e a user telnetting to a remote host can totally access the host computer if he logged in as a root)

Network File System/Service : 

Network File System/Service The Network File System (NFS) was developed to allow machines to mount a disk partition on a remote machine as if it were a local disk. It allows for fast, seamless sharing of files across a network. Exported directories are defined in /etc/exports Each entry specifies the hosts to which the filesystem is exported plus associated permission and options

THANK YOU !! : 

THANK YOU !!