I want to assign static ip to my centos server. so i made following changes to /etc/sysconfig/network-scripts/ifcfg-eth0 and the file looks like this.
DEVICE=eth0
TYPE=Ethernet
UUID=16e5310e-f477-4031-a17e-121a8c856fa1
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth0"
HWADDR=FC:AA:14:EF:51:41
IPADDR=192.168.0.41
NETMASK=255.255.255.0

PEERDNS=yes
PEERROUTES=yes

but after restarting the system, i am unable to access internet until i run dhclient command at the prompt.
kindly please someone help me in fixing this.

Try using "BOOTPROTO=none".

THanks for the reply.

I sorted out the problem by entering the "dhclient eth0" to the file /etc/rc.d/rc.local, so that i no need to run dhclient cmd after rebooting the server everytime.

NOW my ip is 192.168.0.41.

But i am able to access the server even by entering my old ip as http://192.168.0.7/myapp

is there any way to restrict it.

By setting up a static IP address your computer does not automatically acquire any DNS server information so you can not access the Internet using URLs I.e. Google.com etc. if you run dhclient then from rc.local you will reassign the IP address as well as get the DNS server info.

I'm lazy and use the router's dhclient address reservation feature but you should be able to use network manager setup if running a desktop or system-config-network from the command line. Fill in the info using your ISP DNS servers or many use google's 8.8.8.8

Personally I've always found Network Mgr to be a pain, so I always turn it off, then it will just do as its told.
(As michaelk points out, this only sets the local IP - it won't update DNS)

Simply edit (or create) /etc/resolv.conf (should be there). For example, here's what it looks like for Google's open DNS servers:
You only need two, more is just overkill.

I would note that router DNS may cease working after some period of time; this happens with some Linksys routers and I've seen it on others. After a while, it just quits and needs to be restarted.

The configuration I use for fixed-IP on all my systems looks like this:
Keep in mind that DHCP usually starts leasing at 192.168.1.100, so keep your fixed-IP below that.

Hope this helps some.

Oops! Forgot to mention /etc/hosts.

This is my /etc/hosts file for four servers and one network printer:
The names are the hostname you assigned to the box during installation. fubar.lan is the actual name of the host, fubar is how you refer to it without the .lan.

So, you ping snafu from fubar (or, for that matter ping fubar from fubar) and get a response. You also ssh fubar from any other server without having to enter the numeric address.

Every box has the same /etc/hosts file, every box can access the network printer (HPLIP runs on every system; HPLIP set up also sets up CUPS).

Makes life easier.

the original configuration seems to be missing the gateway, an easy way to check is by running "ip route" and make sure you have a default gateway. By getting the ip using dhcp, you will also have a default gateway assigned, the "ip route" cmd will show it too.

You're missing gateway and dns1/2 in your ifcfg file, and change bootproto from static to none.

An example from one of my systems:
192.168.1.2/3 are VMs on my network running dnsmasq to provide local name resolution.

NetworkManager will use the DNS1/2 entries in your ifcfg file to populate resolv.conf, you shouldn't modify resolv.conf manually if you're using NetworkManager.