ip address for google dns servers

Configure your network settings to use the IP addresses 8.8.8.8 and , name server using Google's infrastructure, try Google's Cloud DNS. If you're not familiar with what exactly DNS servers do they translate the web address you type into your browser into the actual IP address. Before Google started doing public DNS service on 8.8.8.8, 8.8.4.4 an Internet connectivity you can do is to ping an IP address, When a new device connects to them, they automatically dish out IP addresses and DNS server information.

Google Public DNS IP addresses, Google Public DNS IP addresses (IPv4)
DNS 8.8.8.8 and 8.8.4.4 The Google Public DNS IPv6 addresses and 2001:4860:4860::8888 and 2001:4860:4860::8844. 

On Mac and Linux IPv4 dig @8.8.8.8 www.example.com. +cd IPv6 dig @2001:4860:4860::8888 www.example.com. AAAA +cd. Verify that another open resolver can resolve the selected hostname At the command prompt.

On Windows
nslookup www.example.com. 4.2.2.1
nslookup www.example.com. 4.2.2.2
nslookup www.example.com. 208.67.222.222
nslookup www.example.com. 208.67.220.220
On Mac and Linux
dig www.example.com. @4.2.2.1
dig www.example.com. @4.2.2.2
dig www.example.com. @208.67.222.222
dig www.example.com. @208.67.220.220