Thursday 15 September 2011

Basic network configurations ip, hosts file, portmap and xinetd services

In this article we will discuss all those necessary steps which you need to perform before solving networking related questions in RHCE exam. Don't skip this tutorial, giving few minutes to this could save you from huge problems in exam. All steps are given in a sequences don't skip them whether you them or not.

Check LAN card driver is installed or not.

LAN driver is the top most part for network. To check it run setup command
setup commands
Select network configuration from list

If you see LAN card here mean you have LAN driver
select lan card
if you don't see here anything and Linux drop you back on list manu means you don't have LAN driver. Install is first.
If you don't know how to install LAN driver then follow this link.Installing lan card driver, location of important networking files and descriptions

Check proper IP configuration

All systems on RHCE exam should have an properly configured IP address. During this entire practical we are using three systems. There description is given belowCheck these systems for properly configured IP address. you can review our pervious article if you feel trouble in IP configuration.Network configuration commands ip ifconfig ping netstat arp mii-tool
Node Operating system Name IP
PC1 Linux RHEL Server
PC2 Linux RHEL Client1
PC3 Windows XP Client2

Change host name

If you have skipped hostname during installation then it would be localhost.localdomain.You can change hostname with hostname command but this change would be temporary. To change hostname permanently do editing in /etc/sysconfig/network.
set computer name as shown in table.
#vi /etc/sysconfig/network
On server system set it to Server and in client system set it Client1

Check /etc/hosts files for name resolution

Several Linux server depend name resolution. This file should have entry of all network systems.It will save you from naming related problem. In our network it should look like this on both Linux system Server and Client1
hosts files

Check firewall status

Firewall is the necessary security part of Linux system which is connected to Internet. But in exam we are not going to use Internet so it’s good practice to disable it.
To disable firewall run setup commands
Now select firewall configuration from list and click on run tool
select firewall configurations
Select disable and click on ok and quit to return on command prompt.
diable firewall
System reboot require to take effect so reboot system with reboot -f commands

Check portmap and xinetd package status

Almost every Linux server needs these two rpm to function properly. First check that these rpm are install or not. If no rpm is install then install them via rpm commands. If you don't know how to install rpm then follow this link.Linux RPM Red Hat's Package Manager
rpm status
If you have rpm then check there status via setup commands
Now select system service from menu
select system service
put a star in front the portmap service
select portmap
Now put star in front the xinetd service
Click on ok and select quit to come back on command prompt
Now restart these two service.
service restart
To keep on these services after reboot on then via chkconfig command
After reboot verify their status. It must be in running condition
service status
Once you have successfully completed these steps you are ready to configure the Linux server Good Luck.