set static ip ubuntu

1. Set IP changes in "/etc/network/interfaces"

auto eth0
iface eth0 inet static

address 136.187.xx.xx
netmask 255.255.248.0
gateway 136.187.80.1

2. Don't give your DNS configurations in /etc/resolv.conf because while we restart the server sometimes the configuration get erased.
 So use vim /etc/resolvconf/resolv.conf.d/base (while updating configs in this it doesn't get removed).

search  (domain name)
nameserver 8.8.8.8
nameserver 8.8.4.4