This method requires no software, no fancy router settings/models, and doesn't affect any other devices on your network. It works in sleep mode, too.

1. On your PC, go to OpenDNS.com and start up a free account: https://www.opendns.com/

2. add a network and use the default IP that shows up: https://dashboard.opendns.com/settings/
*This is your modem's IP, not your PC's IP. you can double check at http://www.whatismyip.com/

3. Click your IP address as it's listed to go to your CONTENT EDITING page. Keep the categories set at NONE but add these individual domains near the bottom to block:
nus.c.shop.nintendowifi.net
nus.cdn.c.shop.nintendowifi.net
nus.cdn.wup.shop.nintendo.net
c.shop.nintendowifi.net
nus.wup.shop.nintendo.net
nus.cdn.shop.wii.com (*may prompt a "block entire content delivery category?". Choose No/Domain only.)


4. On your 3DS: System Settings > Internet Settings > Connection Settings > Connection # > Change Settings > DNS > Auto-Obtain NO > Detailed Setup

5. Set Primary DNS to 208.67.222.222 and secondary to 208.67.220.220

6. Enjoy life

In case it's not working:
Are you using another DNS? If you have a custom DNS (such as google DNS) setup on your router, this might not work. You can clear the router's DNS settings and set up Google DNS on your PC to keep using GoogleDNS with your computer, and OpenDNS from your 3DS.

Be sure to disable any proxy or VPNs for Step 2. Don't know if you have one? http://www.whatismyip.com/ will tell you if it detects a proxy, and if it's giving you incorrect location/ISP details, you might be running a VPN/proxy.

You might have a Dynamic IP (a home IP/step 2 IP that changes once in a while). OpenDNS has documentation on how to deal with this.'

OpenDNS only offers one free IP setup per account. If you connect to another router OpenDNS won't be able to block the request. (I will explain why this happens in more detail later)

Disclaimer: I know a thing or two about routers, but it is a hobby, not a profession. I might be wrong about the domains blocked. I appreciate any input to make this right in case I'm wrong. So far I haven't been pinged to update, but I also haven't tried to force the update check either. If anyone knows for certain what domain to block, please let us all know so I can edit this post. If the 3DS pings an IP instead of a domain, this OpenDNS method is worthless, but apparently that's not the case so we should be okay.

Spotpass/Streetpass/Homepass Warning: Spotpass will ping the update. Because spotpass hotspots are preconfigured into every 3DS, it will not use OpenDNS. This method will not protect you from downloading the update over spotpass. Also, this is just speculation. Feel free to confirm/disprove this for the rest of us. Homepass can be configured to use OpenDNS, but it's not something I'm going to get into because there are too many unique ways to homepass.

 

[Generalan]

Don't bother with this, just use the tubehax dns.

Is it just a dns I have to type in easily or do I have to buy something or insert something into my sd card to get it to working?
Thanks for replying

EDIT: Also, after I deleted the update data to Omega Ruby, and I got OpenDNS to work, it still didn't let me go online. Does it matter if I have updated Omega Ruby as long as I haven't updated the 3DS itself?

 

[HE1NZ]

If I try accessing browser from old 3DS through emunand and it asks for update, that means I didn't fully blocked network from updates?

 

[urherenow]

If I try accessing browser from old 3DS through emunand and it asks for update, that means I didn't fully blocked network from updates?

That depends... if it was already asking for an update, then it will continue to do so. The only way to clear it out is to boot your 3ds into safe mode, then cancel, then dump your import.db from the sysnand, and inject it into emunand (import.db is what lets your 3ds know there are newer system files available). If you do that, then later on you get asked to update, then updates are not properly blocked. Use rxtools to dump from sysnand, then inject to emunand.

 

[3DSJunkie]

is there another way for doing it on CFW, so that my 3DS never asks me...??? ( ouh and i have a funny thing at my 3ds, if i start rxtools than i see under configs 4.5 but without rxtools i have 6.4, wtf?????)

 

[Kostaspaokara]

I bought from a friend a 3ds with gateway (I think it's gateway).
First question is: Are you able to play online game with this method?
Second question: If yes, are you able to paly it with all kind of fhlash cards like gateway?
Thanks

 

[Ghork]

How does this differ from just blocking the domains in my router?
Im not very knowledgeable when it comes to networking.

 

[TotalInsanity4]

How does this differ from just blocking the domains in my router?
Im not very knowledgeable when it comes to networking.

If you can block them from your router, you should

 

[BasedIndex]

I was surprised that my router already had opendns set up.
Thanks for the tutorial.

 

[Yamagushi]

Is this setup no longer working? I just got an update nag, didn't have anything pop up for about a week with this, then turned the 2DS on today after it was sitting in sleep mode for a while and it has a system update waiting.

 

[James310]

Or use tubehax....

 

[Yamagushi]

Whats the best way to remove the update from emunand? And if I've been in emunand the whole time, the update shouldn't be on sysnand right? I've seen theres some method of getting it off emunand involving using sysnand's database. Is this still the best method, and if I have content installed only in emunand, would using the sysnand database mess that all up?

 

[James310]

Whats the best way to remove the update from emunand? And if I've been in emunand the whole time, the update shouldn't be on sysnand right? I've seen theres some method of getting it off emunand involving using sysnand's database. Is this still the best method, and if I have content installed only in emunand, would using the sysnand database mess that all up?

Why not just update emunand? That's kinda the whole point of it,..

 

[Yamagushi]

Why not just update emunand? That's kinda the whole point of it,..

Didn't realize it was safe to.

 

[kyle9252]

It works! 11.1 4ever(untill I can downgrade)

 

[CrazyLukeHD]

For anyone who doesn't want to use OpenDNS, use this method if your firmware is updated.
WARNING: Only use this method on emuNAND. Using this method on sysNAND will result in a brick!

1. Use 3DNUS to download update files for the specific version you want (Ex. 11.0.0-33U)

2. After it's done, a folder with the firmware version should appear in the same folder as 3DNUS. Rename that to "updates".

3. Copy the "updates" folder to the root of your SD card.

4. Use sysUpdater to downgrade your emuNAND firmware (Once opened, just press Y and after a few minutes the system will restart).

After that you should have your previous firmware version restored.

 

[Jayro]

Doesn't Luma already do this behind the scenes?

 

[CrazyLukeHD]

Not that I know of.

 

[Jayro]

Oh. Because I heard it blocks updates.

 

[gengardenne]

Hey there is a valid method to still block the update message on 11.3 or 11.4 firmware?
This method is still available?
And there are risk to use it maybe?
I would like to have 1 answer for each one of my questions if possible

 

[MushGuy]

Do you think this will be useful to block these servers from detecting our systems?: https://gbatemp.net/threads/update-regarding-the-recent-3ds-banwave.471781/page-291#post-7346389