OpenDNS offers an alternative your ISP's/organization's own DNS servers. Business and consumer-grade services are available for any budget.

Using OpenDNS servers to perform your DNS resolution can have many benefits, depending on the plan you choose:

• Built-in protection to filter out malicious, phishing & malware domains.
• Parental controls to instantly protect every device in your home.
• Customizable or preset content filtering, such as for adult content.
• Retention of the past year's Internet statistics.
• Restrict Internet access to allowed domains only, to “lock-down”
  your environment.

There are various levels of free and paid OpenDNS plans available. The features available to you will depend upon the plan you use.

• If you want Content Filtering through the Home Basic plan,
  you need to create an account on the OpenDNS website.
• If you don't want Content Filtering, or are using the FamilyShield plan,
  you don't have to create an account.

For more details, see the Home Account FAQ at: Open DNS Home Account FAQ

You can setup OpenDNS for the FamilyShiled plan on FreshTomato in just a few steps.

First, configure the settings:

1. Go to the Network menu
2. In the DNS Server dropdown, select Manual.
3. Enter the two FamilyShield OpenDNS addresses (208.67.220.123 and 208.67.222.123) into the DNS1 and DNS2 fields.
4. Click Save. Your settings should now look like this:
   
   
   
   
   
5. Flush the DNS resolver cache of data from previous lookups. In the Debugging menu, click >> Flush DNS (dnsmasq) cache.
   

Your FreshTomato router should now be using OpenDNS for DNS resolution. You can test this using the nslookup command,
or by using the OpenDNS test page: OpenDNS Test Page

Again, the features available to you will depend on which plan you subscribe to.