NOTE: I no longer use DD-WRT and am unable to answer any questions about it.

OpenDNS is a nice easy way to implement some degree of content control (filtering) on your home network.  They have two ways to accomplish it.

The first is a preconfigured set of filtering designed with family usage in mind.  It may filter more than you actually want to.  On the flip side it does not require an OpenDNS account.  It also cannot be used with the set described below.

The second is customized and relies on a configuration you set.  To do this they rely on your external IP address when the DNS query hits their servers.  If the address is not updated, you may not get your configured filtering.  So it’s important to keep your address updated within your OpenDNS account.  They have a utility which you can install that does an update when you logon to your computer, but that’s not ideal if you don’t use the computer configured to do the update every day.

If you use DD-WRT, a better solution exists.  You can have DD-WRT take care of it by coupling it with DNS-O-MATIC.  DNS-O-MATIC is a helper service offered by OpenDNS that provides updates to OpenDNS.  Here’s how.

First you need to create a DNS-O-MATIC account.  Sign in with your OpenDNS account credentials.  Associate your OpenDNS account and your OpenDNS configured network with DNS-O-MATIC.  Follow their instructions, it’s easy.

Then, Enable Dynamic DNS within DD-WRT:

1. Go to Setup > DDNS
2. Set DDNS Service to “Custom”
3. Set DynDNS Server to “updates.dnsomatic.com”
4. Set Username to DNS-O-Matic login (same as your OpenDNS account).
5. Set Password
6. Set Hostname to “all.dnsomatic.com”
7. Set URL to “https://updates.dnsomatic.com/nic/update?”
8. Set “Do not user external ip check” to Yes
9. Set “Force Update Interval” to the number of days you want to force an update.  I recommend daily, or 1.
10. Click “Apply Settings” button.
11. Click “Save” button.

Now reboot the router.

1. Go to the “Administration > Management” tab.
2. Scroll to the bottom and click the “Reboot Router” button.

Once the router comes up, DD-WRT will send an update to DNS-O-MATIC once per day with your current external IP address.  DNS-O-MATIC will in turn update your OpenDNS configured network with it.

Now to customize the content filtering, login to OpenDNS and configure your network as you see fit, including blacklists and whitelists.  Enjoy!