This is what you will need.
1. Access the router's browser-based utility. Log into your router's browser-based utility by entering 192.168.1.1 into a browser. The username should be blank and default password is "admin" if you are not using Cisco Connect.
2. Go to the "Setup" menu. Click on the "Setup" tab.
3. Go to the "Basic Setup" page. Click the "Basic Setup" page.
4. Enter the first DNS resolver. Enter 22.214.171.124 in the "Static DNS 1" field.
5. Enter the second DNS resolver. Enter 126.96.36.199 in the "Static DNS 2" field.
6. Enter the third DNS resolver. Enter 188.8.131.52 in the "Static DNS 3" field.
7. (Optional) If you're having difficulties with network devices or network printers locally Enter .home into the DHCP domain name to return your DNS search suffix to the router. This is often needed when using certain modems that override the local search suffix.
8. Save your settings. Click "Save Settings" to save your settings.
How to Configure Linksys Router E2500?