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I want to block adult sites not torrents and other. Currently i am using "OpenDNS Home free". i set those free DNS 208.67.222.222 and 208.67.220.220 in router DNS fields and also i have "OpenDNS updater". But the problem is that i used my pc after office. My router's IP changes 3 or 4 times a day(due to restart of router). This means if someone tries to access blocked content(which i blocked in web content filtering) during the day, He will access it. Please tell me if i am wrong.

  1. What to do overcome that problem?
  2. When selecting "OpenDNS Home" Do i need that 2 DNS addresses in the router or it is only for free(not for "OpenDNS Home").
  3. Further if i use static IP(i will buy if required) then will my network be fully secured or dynamic IP will work better?
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2 Answers

The OpenDNS updater is what keeps track of your IP address for OpenDNS. It uses this IP address to track incoming DNS requests to their service. If the updater is on your PC and you take it to work, OpenDNS will no longer be updating your HOME router IP. It will be updating your work IP. If you have other computers being used at your home you need to install the updater on those PC's as well so that OpenDNS knows what YOUR router IP is.

The two DNS IP addresses are not NEEDED but recommended. The purpose is to have a back up in case one goes down.

The use of a static IP address would be easier and more reliable than the dynamic because it will no longer rely on the updater and since the IP never changes, anyone that uses your home internet will always be subjected to the restrictions imposed by the OpenDNS rules.

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You seem to have an inaccurate impression of how networks work. Filtering doesn't require knowing what your IP address is and DNS is not an effective means of filtering content. Filters work by checking the content being requested, not where the content is being requested from. Using a DNS server that doesn't return results will stop a very basic attempt at access to a site, however it is easy to get DNS information from a different DNS server which will allow the DNS filter the be bypassed easily.

In your case, it appears that OpenDNS offers a DNS server that won't return results that match your filters when requested from your IP. You should be able to run the updater on more than one system and can probably get a router that would support making the updates for you automatically.

That said, I'd re-emphasis that this is not an effective means of filtering. It is a trivial thing to make requests to another DNS server and then requests can be made to a "blocked" server without issue. It is no deterrent at all to someone that knows what they are doing and you should expect that someone who wants to bypass it will figure out how to.

The two DNS addresses is just a redundancy standard. Generally at least two DNS servers are entered to make sure that you can still resolve websites if one of the servers is down.

A static IP is easier to work with, but this is not a reason to buy one if you don't have other needs for a static IP. (The main, and really only, reason to need a static IP is if you want to be able to host information on the Internet. And even that situation can be worked around with services like DynDNS.

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I think you don't understand the full set of services provided by opendns. They provide this kind of filtering. –  Mark C. Wallace May 3 '13 at 17:54
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@MarkC.Wallace Oh, I see, the problem he is running in to is that they don't do a preset filter, but a customized one and it is losing the IP of his connection, so they don't know which DNS entries to return and which to fail. –  AJ Henderson May 3 '13 at 18:08
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