unable to connect internet from linux 6

After I installed linux 6, unable to connect internet.

ifconfig eth0 gives IP address and able to ping. my eth0 connection established.

ifup and ifdown works fine but not able to connect internet.

DEVICE="eth0"
BOOTPROTO=dhcp (none) before.
NM_CONTROLLED="yes"
ONBOOT=yes
TYPE="Ethernet"
UUID="e03baa67-c63c-4dc3-a808-dacb408c77e4"
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth0"
IPADDR=xxx.xxx.xxx.xxx
NETMASK=255.255.255.0 was not there
PREFIX=25
GATEWAY=255.255.255.0
DNS1=xxx.xx.xxx.xxx
HWADDR=00:1E:4F:14:FC:C0
LAST_CONNECT=1509674928


open /etc/sysconfig/network-scripts/ifcfg-eth0 file

I added NETMASK and update BOOTPRO none to dhcp.

Now I am able to connect the internet.

Happy learning and share the knowledge to others.