sagemcom f@st 3864 v2 change dns admin password works June 2019


This doesn't work on more recent modems - however the answer is indeed hidden in the whirpool thread posted by IFNI above. It's slightly technical... but only slightly! I'll sumarize the steps here because the whirpool thread is epic and confusing.



1. Visit the following link in your browser: http://192.168.0.1/dumpcfgdynamic.conf

2. It will download a file called "dumpcfgdynamic.conf" to your computer

3. Find the file and rename the .conf to .html - and now open this in a sane browser like Firefox

4. You can now see a bunch of information that looks rather like computer code but is in fact what is known as XML

5. Search for the string "AdminPassword" near the top and you will see a string between the AdminPassword tags - in human language it is between the greater than and less than symbols and looks a bit like "LKJHhjhLJKHL=="  highlight and copy that to your clipboard (ctrl+c)
6. Navigate to the following website https://www.base64decode.org/ and paste the string in the box at the top and press the DECODE button below - a new string will appear in the box below the decode button - that is your admin password so now copy that
7. Now navigate back to http://192.168.0.1/main.html and a password prompt will appear, username is "admin" and the password you just decoded in step 6.

8. You will have now gained access to all the routers advanced settings and can change things like the default DNS

9. Note you will need to enter the password *every* time you go to a new page, so you may want to paste it somewhere convenient



In my case all I wanted to do was block an insiduous and evil game called Roblox that my 12 year old daughter is addicted to - because it loads from a https:// address you cannot block it through the standard parental controls in the router. As such I had to open an account on OpenDNS and apply the new  DNS setting to the router - which you can only change if you access the advanced settings as an admin user - as outlined above. I tried to keep the steps as simple as possible because I'm sure there are many other parents out there who want to block things! I hope it helps somebody Smiley Happy



OpenDNS is a free service by Cisco - create an account here https://www.opendns.com/home-internet-security/  and choose the "OpenDNS Home" option, not the family shield one.



The above worked for me - I have a F@ST3864V2 router with the 8.353.21_F@ST5350_Optus Software (you can find this info after you click Advanced Settings)