Wednesday, July 17, 2013

sudo permission to the normal user

how to give sudo permission for normal user
#visudo

in the configuration file just just change this
#Same thing without a password
# %wheel ALL=(ALL)  NOPASSWD:ALL
 dbuser    ALL=(ALL) NOPASSWD: ALL
:wq!
save and quit

here we have given sudo permission for the normal user
by this normal user has given permission as sudo


Thursday, April 4, 2013

installation of dhcp server in centos6

Installation of DHCP in centos6

first install the dhcp packages in your system
#yum install dhcpd
After installing copy the dhcpd.conf.sample from the desired loaction
#cp /usr/share/doc/dhcp*/dhcpd.conf.sample /etc/dhcpd/dhcpd.conf
Then after this go to dhcpd.conf file
#vim /etc/dhcpd/dhcpd.conf
here it is shown how i edited iam setting the dhcp server ip address as 192.168.1.177 static
# dhcpd.conf
#
# Sample configuration file for ISC dhcpd
#
# option definitions common to all supported networks...
option domain-name "varna.com";
option domain-name-servers 202.65.156.11, 188.18.135.5;
default-lease-time 600;
max-lease-time 7200;
# Use this to enble / disable dynamic dns updates globally.
#ddns-update-style none;
# If this DHCP server is the official DHCP server for the local
# network, the authoritative directive should be uncommented.
#authoritative;
# Use this to send dhcp log messages to a different log file (you also
# have to hack syslog.conf to complete the redirection).
log-facility local7;
# No service will be given on this subnet, but declaring it helps the
# DHCP server to understand the network topology.
subnet 192.168.1.0 netmask 255.255.255.0 {
}
# This is a very basic subnet declaration.
subnet 192.168.1.0 netmask 255.255.255.0 {
range 192.168.1.50 192.168.1.250;
option routers 192.168.1.4;
}
# This declaration allows BOOTP clients to get dynamic addresses,
# which we don't really recommend.
#subnet 10.254.239.32 netmask 255.255.255.224 {
# range dynamic-bootp 10.254.239.40 10.254.239.60;
# option broadcast-address 10.254.239.31;
# option routers rtr-239-32-1.example.org;
#}
# A slightly different configuration for an internal subnet.
#subnet 10.5.5.0 netmask 255.255.255.224 {# range 10.5.5.26 10.5.5.30;
# option domain-name-servers ns1.internal.example.org;
# option domain-name "internal.example.org";
# option routers 10.5.5.1;
# option broadcast-address 10.5.5.31;
# default-lease-time 600;
# max-lease-time 7200;
#}
# Hosts which require special configuration options can be listed in
# host statements. If no address is specified, the address will be
# allocated dynamically (if possible), but the host-specific information
# will still come from the host declaration.
#host passacaglia {
# hardware ethernet 0:0:c0:5d:bd:95;
# filename "vmunix.passacaglia";
# server-name "toccata.fugue.com";
#}
# Fixed IP addresses can also be specified for hosts. These addresses
# should not also be listed as being available for dynamic assignment.
# Hosts for which fixed IP addresses have been specified can boot using
# BOOTP or DHCP. Hosts for which no fixed address is specified can only
# be booted with DHCP, unless there is an address range on the subnet
# to which a BOOTP client is connected which has the dynamic-bootp flag
# set.
#host fantasia {
# hardware ethernet 08:00:07:26:c0:a5;
# fixed-address fantasia.fugue.com;
#}
# You can declare a class of clients and then do address allocation
# based on that. The example below shows a case where all clients
# in a certain class get addresses on the 10.17.224/24 subnet, and all
# other clients get addresses on the 10.0.29/24 subnet.
#class "foo" {
# match if substring (option vendor-class-identifier, 0, 4) = "SUNW";
#}
#shared-network 224-29 {
# subnet 10.17.224.0 netmask 255.255.255.0 {
# option routers rtr-224.example.org;
# }
# subnet 10.0.29.0 netmask 255.255.255.0 {
# option routers rtr-29.example.org;
## }
# pool {
# allow members of "foo";
# range 10.17.224.10 10.17.224.250;
# }
# pool {
# deny members of "foo";
# range 10.0.29.10 10.0.29.230;
# }

Then save the file

After this start the dhcp service
#service dhcpd start

to start the service when were the system starts
#chkconfig dhcpd on

then check in other system by disconnecting and again coonect to internet
then you will see new dhcp server