Force the use of OpenDNS with an Edimax router

Question

I am using an Edimax router on my home network and have set the default DNS addresses to those of OpenDNS's Family Shield. But now I realise the protection is safe only if I force the use of OpenDNS from the router and block any request to an exterior DNS service.

So what I need to do is - see this discussion on their forums and here - to create a new filtering rule on my Edimax router to disable outbound UDP 53 traffic for my LAN. I can do this as shown page 50 of my router's manual.

The problem is that I lose all internet connectivity after creating these rules. I can't figure out how to allow the traffic to go through OpenDNS's addresses in my router.

Here is what I did :

1/ Make OpenDNS the default DNS provider :

2/Disable outbound UDP 53 traffic for my LAN :

3/ This is my problem : how can I add a second rule that allows port 53 tcp,udp to OpenDNS's servers ? The "Outbound IP filtering" only allows to set blocking filters.

Any suggestions ?

Note

• The problem here is from the router because I'd like an OS-independent solution.

Answer 1

You have to consult the manual on how to allow specific IPs and ports.

If the router does not support rules to open a specific ip:port, you could deny the range of IPs combinatorially preceding and succeeding the IP you want to leave open. As in:

1 block
2 block
3 open
4 block
5 block

It makes more sense to place a rule to allow traffic to a specific server -before- denying all other traffic. Otherwise the packets would never make it the the rule that allows them to leave the filter (at least that's how it works with Linux netfilter).