NETWORK BASICS
Here we are providing some idea about network and network commands
To check IP address and IP information #ifconfig
To set IP address #setup
network configuration select ethernet give IP address, subnet mask, gateway close quit quit #service network restart
To provide DNS information: #vi /etc/resolv.conf (type as follows) nameserver (DNS IP) ex: nameserver 202.138.103.100 save&quit
To check network connectivity: Ping: packet internet gropher #ping server IP
To check LAN card status: #ping 127.0.0.1
To check host name: #hostname
To change host name: #hostname (fqdn) ex: #hostname station1.redhat.com
To assign new hostname permanently #vi /etc/hosts add a new line ex: 192.168.0.1 station1.redhat.com station1 save&quit
#vi /etc/sysconfig/network edit as follows hostname= ex: hostname=station1.redhat.com
To view current version of kernel #uname -r
To view current run level: #runlevel
we have 6 run levels: runlevel 0=shutdown runlevel 1=single user mode runlevel 2=multi user without nfs runlevel 3=multi user with network(only text mode) runlevel 4=un used runlevel 5=multi user with graphics & network runlevel 6=reboot
#netstat -ant it will gives network statistics(which port number of the server is connected to which port number of client) #vi /etc/sysconfig/network-scripts this is the directory stores networking information #ifcfg-eth0 this command gives gateway, boot protocol, netmask details this is the file which stores IP addresses and networking details
ifdown : this command is used to down the device ifup : this command is used to bring the interface up device