In my last article I had shared the steps and instructions to configure NIC bonding and teaming in Red Hat Linux using various bonding types like MII, ARP etc
Configuring network in Red Hat Linux can be hectic and confusing if you don't know the parameter details which are used. Also from Red Hat 6 the configuration parameter has been changed for network-config. Let me show you out the steps to do the same along with some possible explanation.
The Interface device which controls the network of your Linux machine is mostly eth0 which is the default NIC interface in the system.
There can be multiple NIC in your system which might be denoted as eth1, eth2 and so on.
The configuration files used for complete network configuration in Red Hat 6 are
/etc/sysconfig/network-scripts/ifcfg-eth0 (can vary as per the NIC present)
/etc/nsswitch.conf
/etc/resolv.conf
Command Line configuration
Step 1 :
Here below is a sample file configuration for ifcfg-eth0
# less /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
HWADDR=73:25:N4:2E:8C:46
TYPE=Ethernet
UUID=ca73df13-5553-4631-bfb4-9244f5e29190
ONBOOT=yes
NM_CONTROLLED=no
IPADDR=10.10.20.55
DNS1=8.8.8.8
GATEWAY=10.10.20.100
NETMASK=255.255.255.0
BOOTPROTO=none
USERCTL=no
PEERDNS=yes
Now let me just explain theese configuration parameters
DEVICE = *name*
name : It is the name of the physical device
HWADDR = *MAC-Address*
MAC-Address : It is the hardware address of the Ethernet device in the form AA:BB:CC:DD:EE:FF. This directive must be used in machines containing more than one NIC to ensure that the interfaces are assigned the correct device names regardless of the configured load order for each NIC's module.
TYPE = *device*
device : Mention if the NIC device you are connecting is Ethernet or Wifi device
UUID = *xx-xx-xx*
This is used by the Network Manager and is self generated so in case you are not using Network Manager this field is not required. Do not manually edit this line
ONBOOT = *answer*
where answer can be one of the following
- yes — This device should be activated at boot-time.
- no — This device should not be activated at boot-time.
NM_CONTROLLED = *answer*
where answer is one of the following:
- yes — NetworkManager is permitted to configure this device.This is the default behavior and can be omitted.
- no — NetworkManager is not permitted to configure this device.
IPADDR = *IPv4 address*
Give the IPv4 address of your system
DNS1 = *nameserver*
nameserver : where address is a name server address to be placed in /etc/resolv.conf if the PEERDNS directive is set to yes
GATEWAY = *address*
address : Give the gateway address of your network
NETMASK = *address*
address : Give the netmask address of your network
BOOTPROTO = *protocol*
where protocol is one of the following:
- none — No boot-time protocol should be used.
- bootp — The BOOTP protocol should be used.
- dhcp — The DHCP protocol should be used.
USERCTL = *answer*
where answer is one of the following:
- yes — Non-root users are allowed to control this device.
- no — Non-root users are not allowed to control this device.
PEERDNS = *answer*
where answer is one of the following:
- yes — Modify /etc/resolv.conf if the DNS directive is set. If using DHCP, then yes is the default.
- no — Do not modify /etc/resolv.conf.
Step 2:
Configure /etc/resolv.conf
In case you have used directive no for the parameter PEERDNS then you will have to manually update your resolv.conf file.
# vi /etc/resolv.conf
nameserver 8.8.8.8
Step 3:
Configure /etc/nsswitch.conf
#hosts: db files nisplus nis dns
hosts: files dns
Start your network services
# service network restart
or
# /etc/init.d/network restart
To check the ip details of your machine
# ifconfig
eth0 Link encap:Ethernet HWaddr 73:25:N4:2E:8C:46
inet addr:10.10.20.55 Bcast:10.10.20.255 Mask:255.255.255.0
inet6 addr: fe20::7a35:c4gf:fe2e:8c46/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:642049 errors:0 dropped:0 overruns:0 frame:0
TX packets:28185 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:74176258 (70.7 MiB) TX bytes:6418581 (6.1 MiB)
GUI configuration
GUI configuration can be done either on command line as well as on the GNOME or KDE desktop.
Make sure the following package is installed
# rpm -qa | grep system-config-network
system-config-network-tui-1.6.0.el6.2-1.el6.noarch
# system-config-network
Follow the screenshots (Click on the image for clear view)
Hit Enter on "Device Configuration"
Select the device and hit Enter
Fill up the required details as shown below and click on OK
Once you click on OK you will reach on the first page of action. Select DNS Configuration and hit enter
Fill up the required details as shown below and hit Enter
Once you have filled up all detail move the cursor to Save and Quit and Hit Enter
Restart your network to make the change affect
# service network restart
or
# /etc/init.d/network restart