How to Fix IP by DHCP issue in Ubuntu Jaunty 9.04

There seems to be a major DHCP issue in ubuntu jaunty 9.04 . Many people using this version of ubuntu seem to have problems with getting an ip via DHCP. Even using the dhclient command fails to provide ubuntu with an ip . The dhclient command gives a NO DHCP OFFERS output . So here's a small fix for this in ubuntu . Special thanks to Iowan from Ubuntuforums for this :

Step 1 : Go to the Terminal (Applications->Accessories->Terminal)
Step 2 : First lets make a backup copy of the dhclient.conf file , do this by typing sudo cp /etc/dhcp3/dhclient.conf /etc/dhcp3/dhclient.conf.bak
Step 3 : Then type sudo gedit /etc/dhcp3/dhclient.conf
Step 4 : Here's how the dhclient.conf would look like

# Configuration file for /sbin/dhclient, which is included in Debian's
# dhcp3-client package.
#
# This is a sample configuration file for dhclient. See dhclient.conf's
# man page for more information about the syntax of this file
# and a more comprehensive list of the parameters understood by
# dhclient.
#
# Normally, if the DHCP server provides reasonable information and does
# not leave anything out (like the domain name, for example), then
# few changes must be made to this file, if any.
#


option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;

send host-name "";
#send dhcp-client-identifier 1:0:a0:24:ab:fb:9c;
#send dhcp-lease-time 3600;
#supersede domain-name "fugue.com home.vix.com";
#prepend domain-name-servers 127.0.0.1;
request subnet-mask, broadcast-address, time-offset, routers,
domain-name, domain-name-servers, domain-search, host-name,
netbios-name-servers, netbios-scope, interface-mtu,
rfc3442-classless-static-routes, ntp-servers;

#require subnet-mask, domain-name-servers;
#timeout 60;
#retry 60;
#reboot 10;
#select-timeout 5;
#initial-interval 2;
#script "/etc/dhcp3/dhclient-script";
#media "-link0 -link1 -link2", "link0 link1";
#reject 192.33.137.209;

#alias {
# interface "eth0";
# fixed-address 192.5.5.213;
# option subnet-mask 255.255.255.255;
#}
#lease {
# interface "eth0";
# fixed-address 192.33.137.200;
# medium "link0 link1";
# option host-name "andare.swiftmedia.com";
# option subnet-mask 255.255.255.0;
# option broadcast-address 192.33.137.255;
# option routers 192.33.137.250;
# option domain-name-servers 127.0.0.1;
# renew 2 2000/1/12 00:00:01;
# rebind 2 2000/1/12 00:00:01;
# expire 2 2000/1/12 00:00:01;
#}

Step 5 : Now in this file , there are two instances of rfc3442 , the first instance is the declaration and the second instance is where it is used.
Step 6 : Now the first instance , should be commented out ( NOTE: You can comment out a line , by inserting a # in front of the line ) and the second instance can be deleted.
Step 7 : So here's what you should do

# Configuration file for /sbin/dhclient, which is included in Debian's
# dhcp3-client package.
#
# This is a sample configuration file for dhclient. See dhclient.conf's
# man page for more information about the syntax of this file
# and a more comprehensive list of the parameters understood by
# dhclient.
#
# Normally, if the DHCP server provides reasonable information and does
# not leave anything out (like the domain name, for example), then
# few changes must be made to this file, if any.
#

#Comment out this line
#option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;

send host-name "";
#send dhcp-client-identifier 1:0:a0:24:ab:fb:9c;
#send dhcp-lease-time 3600;
#supersede domain-name "fugue.com home.vix.com";
#prepend domain-name-servers 127.0.0.1;
request subnet-mask, broadcast-address, time-offset, routers,
domain-name, domain-name-servers, domain-search, host-name,
netbios-name-servers, netbios-scope, interface-mtu,
rfc3442-classless-static-routes, ntp-servers;
#Delete this section
#require subnet-mask, domain-name-servers;
#timeout 60;
#retry 60;
#reboot 10;
#select-timeout 5;
#initial-interval 2;
#script "/etc/dhcp3/dhclient-script";
#media "-link0 -link1 -link2", "link0 link1";
#reject 192.33.137.209;

#alias {
# interface "eth0";
# fixed-address 192.5.5.213;
# option subnet-mask 255.255.255.255;
#}
#lease {
# interface "eth0";
# fixed-address 192.33.137.200;
# medium "link0 link1";
# option host-name "andare.swiftmedia.com";
# option subnet-mask 255.255.255.0;
# option broadcast-address 192.33.137.255;
# option routers 192.33.137.250;
# option domain-name-servers 127.0.0.1;
# renew 2 2000/1/12 00:00:01;
# rebind 2 2000/1/12 00:00:01;
# expire 2 2000/1/12 00:00:01;
#}

Step 8 : So after making the changes , your dhclient.conf should look like this

# Configuration file for /sbin/dhclient, which is included in Debian's
# dhcp3-client package.
#
# This is a sample configuration file for dhclient. See dhclient.conf's
# man page for more information about the syntax of this file
# and a more comprehensive list of the parameters understood by
# dhclient.
#
# Normally, if the DHCP server provides reasonable information and does
# not leave anything out (like the domain name, for example), then
# few changes must be made to this file, if any.
#


#option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;

send host-name "";
#send dhcp-client-identifier 1:0:a0:24:ab:fb:9c;
#send dhcp-lease-time 3600;
#supersede domain-name "fugue.com home.vix.com";
#prepend domain-name-servers 127.0.0.1;
request subnet-mask, broadcast-address, time-offset, routers,
domain-name, domain-name-servers, domain-search, host-name,
netbios-name-servers, netbios-scope, interface-mtu,
ntp-servers;

#require subnet-mask, domain-name-servers;
#timeout 60;
#retry 60;
#reboot 10;
#select-timeout 5;
#initial-interval 2;
#script "/etc/dhcp3/dhclient-script";
#media "-link0 -link1 -link2", "link0 link1";
#reject 192.33.137.209;

#alias {
# interface "eth0";
# fixed-address 192.5.5.213;
# option subnet-mask 255.255.255.255;
#}
#lease {
# interface "eth0";
# fixed-address 192.33.137.200;
# medium "link0 link1";
# option host-name "andare.swiftmedia.com";
# option subnet-mask 255.255.255.0;
# option broadcast-address 192.33.137.255;
# option routers 192.33.137.250;
# option domain-name-servers 127.0.0.1;
# renew 2 2000/1/12 00:00:01;
# rebind 2 2000/1/12 00:00:01;
# expire 2 2000/1/12 00:00:01;
#}

Step 9 : Thats it , once changes have been made , just save the file and exit
Step 10 : Now restart networking , by typing sudo /etc/init.d/networking restart
Step 11 : Thats it , now you should be getting an ip via DHCP

NOTE: Incase you face any issues , just use the backup file to restore the old file.