Lesson 5

Dates: 6/12/2017
Linux networking
Linux System Administration


Configuring Linux on a network


  • HOWTO configure the network interface and routing by
    using commands /sbin/ifconfig and /sbin/route

    Command to check the interface configuration: 
    /sbin/ifconfig -a
    or 
    ip addr list
    Command to check the routing configuration: 
    /sbin/route -n
    or 
    netstat -nr

    Command to stop the interface: 
    /sbin/ifconfig eth0 down
    or 
    /sbin/ifdown eth0

    Command to configure the interface: 
    /sbin/ifconfig eth0 192.168.5.18 netmask 255.255.255.0 up
    Command to configure the routing to the gateway: 
    /sbin/route add default gw 192.168.5.240 eth0

  • HOWTO Configure the network interface and routing by using the startup scripts.

    Static IP address configuration on Ubuntu in /etc/network/interfaces 
    auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address 192.168.5.18
netmask 255.255.255.0
gateway 192.168.5.240

    Dynamic (DHCP) configuration on Ubuntu: 
    auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp


    Static IP address configuration on RedHat:
    Specific settings for the network cards go into the config files in directory /etc/sysconfig/network-scripts. For example, /etc/sysconfig/network-scripts/ifcfg-eth0 
    DEVICE=eth0
TYPE=Ethernet
ONBOOT=yes
BOOTPROTO=none
IPADDR=192.168.5.18
NETMASK=255.255.255.0
NETWORK=192.168.5.0
BROADCAST=192.168.5.255

    Dynamic (DHCP) configuration on RedHat:
    The interface configuration file for eth0, /etc/sysconfig/network-scripts/ifcfg-eth0: 
    DEVICE=eth0
TYPE=Ethernet
ONBOOT=yes
BOOTPROTO=dhcp

    For the name resolution, configure /etc/hosts, /etc/resolv.conf, /etc/nsswitch.conf

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