Thursday, 9 October 2014

DHCP3-Server Installation and Configuration in Ubuntu 12.04LTS..............

1:-Set a static IP address in Ubuntu 12.04

It is not intuitively obvious how to assign Ubuntu 12.04 LTS a a static IP address from the command line. However, much of Linux administration involves the editing of text files, and assigning a static IP address is no different. You’ll need to edit the following file:

/etc/network/interfaces


Initially, the file only contains information about your local loopback address:

auto lo
iface lo inet loopback



To assign a static IP address, you’ll need to make some changes to this file.
Let’s say you want to assign a static IP of 192.168.0.2 to your eth1 network connection (the first Ethernet adapter on your system; if you only have one, it will be eth0), with a subnet mask of 255.255.255.0 and a local gateway of 192.168.0.1. First, make a backup copy of the interfaces file:


sudo cp /etc/network/interfaces ~


This will make a backup copy in your home directory in case something goes amiss during the editing process. Next, fire up a text editor:

sudo vi /etc/network/interfaces






iface eth0 inet static
address 192.168.0.1
netmask 255.255.255.0
gateway 192.168.0.1


You’ll then to need have your system load the new IP configuration. You can do that by rebooting, but if that takes too long, you can use this command to force Ubuntu to re-read the configuration files:


sudo ifup eth0


Your system will then have a static IP address.

 2:-Installation and Configuration of DHCP3-Server

First, go to a Terminal window and install the DHCP server software, dhcp3-server:
  apt-get install dhcp3-server

once we have your static IP, you’ll need to edit DHCP’s main configuration file, which is /etc/dhcp3/dhcpd.conf. First make a backup copy of the file to your home folder, in case something goes wrong:

 cp /etc/dhcp3/dhcpd.conf ~

Then begin editing dhcpd.conf:

gedit /etc/dhcp3/dhcpd.conf

Could not reliably determine the server's fully qualified domain name?


ubuntu 12.04 and older

This is just a friendly warning and not really a problem (as in that something does not work).
If you insert a
ServerName localhost   
in either httpd.conf or apache2.conf in /etc/apache2 and restart apache the notice will disappear.
If you have a name inside /etc/hostname you can also use that name instead of localhost.

And it uses 127.0.1.1 if it is inside your /etc/hosts:
127.0.0.1 localhost
127.0.1.1 myhostname
Preferred method
Troubleshooting Apache
If you get this error:
apache2: Could not determine the server's fully qualified domain name, 
using 127.0.0.1 for ServerName
then use a text editor such as "sudo nano" at the command line or "gksudo gedit" on the desktop to create a new file,
sudo nano /etc/apache2/conf.d/fqdn
or
gksu "gedit /etc/apache2/conf.d/fqdn"
then add
ServerName localhost
to the file and save. This can all be done in a single command with the following:
 echo "ServerName localhost" | sudo tee /etc/apache2/conf.d/fqdn
But on Ubuntu 14.04:
 echo "ServerName localhost" | sudo tee /etc/apache2/conf-available/fqdn.conf
 sudo ln -s /etc/apache2/conf-available/fqdn.conf /etc/apache2/conf-enabled/fqdn.conf
Don't forget the ".conf" (without will not work).