Apr 14

How I use unblock-us on Roku and/or opendns with my Comcast gateway (or your own with Comcast firmware).

The pain of using a Comcast modem and trying to use unblockus or opendns is that Comcast will not allow the Gateway’s DNS to be changed.

Explanation:

Most solutions that is have seen involve putting your gateway in full bridge mode and using your own router and Wifi. I really didn’t like this solution as that is really doubling up on hardware ( not to mention the inconvenience of resetting my router rules and wifi password on all devices).

My solution is achieved through DHCP.  The DNS is set through the DHCP options. So we will set up our own DHCP server.  But there is another problem. The Comcast gateway won’t let us turn off DHCP!  So we have to change it so that it is only giving out one IP address.  Whatever computer gets that address will not have the correct DNS settings!!!  So make sure the correct computer gets the first (non-correct DNS) IP address by turning all other devices off while setting this up)

Solution:

1) (If you have a dedicated computer that is always on) Set up a DHCP server on your dedicated computer with a Static IP.  I have one always on for Plex and PlayOn so that is the computer I set it up on.  Set up a DHCP scope starting with a high ip address (like 100) and with your desired DNS settings. Stop the DHCP service.  Go to step 3

2) (If you do NOT have a dedicated computer that is always on)Get a small device that has DHCP Server capabilities.  I got a TP-Link TL-WR710N for ~$22 on Amazon.  Set up a DHCP scope starting with a high ip address (like 100) and with your desired DNS settings.  Stop the DHCP and/or turn off the TP-Link.  (Here is my TP-Link Config for Unblock-us, username and password is Admin/unblockus15, and must be on Firmware 140922, and disable wireless in wireless settings on the TP-Link, ip of TP-Link will be 10.0.0.99)

3) After you have your DHCP server up and running log into your Comcast Gateway. Go to Connection -> Local IP Configuration.  And change your Beginning and Ending IP address to the same IP.  Set the DHCP Lease Time to forever.

Comcast-DHCP

4) Turn the device/computer on that you don’t care gets the wrong DNS.  it will get the IP you set above.

5) Start your DNS server (on the computer or the dedicated TP-Link type device).

6) Now you should be able to turn your devices back on and they should get the New IP and DNS!

 

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