Firewall configuration to block 8.8.8.8

[shyam87]

I've got a Talktalk Wifi Hub 2.

I've created a firewall rule to block all communication from LAN to 8.8.8.8.

The rule is sitting at the top, so it is the first rule to be applied.

However, my LAN devices can still reach the destination.

I've restarted the router after adding the rule but that hasn't changed anything.

Any thoughts on what might be the issue?

[Philile-TT]

@KeithFrench thank you. 

[KeithFrench]

Unless you have very specific needs your firewall should have no rules in it and be left at it's default level of medium.

[shyam87]

I certainly will take it up with them. 

But my question is still the same - the one I originally asked. 

What's wrong with my firewall configuration? Is it not supposed to work as intended?

[KeithFrench]

Before your device can reach a website, the URL, e.g. youtube.com, must be converted to an IP address. This is because a URL is not routable; only an IP address is. The whole purpose of DNS is to resolve a URL to its IP address. If this is not working for whatever reason, then that device will not be able to reach that website.

This is an IP networking fact.

If your Echo continues to use Google DNS (8.8.8.8) and you don't like that, take this up with their technical support, not TalkTalk.

[shyam87]

Why would it not have Internet access? The other devices in my network are working fine with the custom configuration so the Echo show should have no problem with it.

And more importantly, what's wrong with my Talktalk router's firewall configuration? Why is the block rule allowing traffic?

[KeithFrench]

I did say earlier @shyam87 that if you block any DNS requests from a device, that device will not have any internet access.

Just because one device uses a different DNS server than other devices connected to the same router, it will have no impact on the performance of the internet connection. Unless, of course, there is a temporary problem with that DNS server.

Do you actually have any problems on your network? If not, just leave it as it is.

[shyam87]

Factory resetting the device hasn't helped. It has received the DNS servers configured on the Talktalk router, but overrides with 8.8.8.8 as the primary, followed by my custom configuration.

So blocking with a firewall seems like the only option.

Does the firewall configuration on the Talktalk router not work as expected? 

[Mandisa-TT]

Hi @shyam87 let us know if you still need assistance. 

[KeithFrench]

Hi @shyam87 

Why would you even want to block DNS traffic? It is essential to the working of the internet. There is nothing wrong with having some of your devices use different DNS servers.

[siphosethu-TT]

Hi there @shyam87, please do as @KeithFrench has stated and will take if form there. Thanks

[KeithFrench]

Hi @siphosethu-TT & @shyam87 

It is the Echo Show that needs to be returned to Factory Settings, not the router.

[siphosethu-TT]

Thank you @KeithFrench, please take note of the above @shyam87. Everything @KeithFrench has said above will help. Thanks

[KeithFrench]

If your DNS rule in your firewall worked, your Echo Show will not be able to access the internet. It is simple to change it back to using the TalkTalk DNS, though. From a quick Google search:-

1. Swipe down from the top of the Echo Show screen to open the quick settings menu. 
2. Select Settings (the gear icon).
3. Scroll down and select Device Options. 
4. Select Reset to Factory Defaults. 
5. Choose the option that best suits your needs:
   • Reset to Factory Defaults: This option removes all data and deregisters the device from your Amazon account, which is ideal for selling or giving away the device. 
   • Reset to Factory Defaults but retain Smart Home Device Connections: This option keeps your smart home devices linked, which is useful for moving the device within the same house. 
6. Follow the on-screen prompts to complete the reset. 

[siphosethu-TT]

Hi there @shyam87, please try completing a factory reset as @ferguson suggested. I've provided a link with steps below. 

Restore your router to factory settings

[ferguson]

Have you tried a factory reset?

[shyam87]

Echo show

[ferguson]

What device is it? 

[shyam87]

I have a device on my network that's overriding the DNS servers configured on the Talktalk router and using 8.8.8.8 as the primary DNS.

Don't think I can change anything on the device to control this behaviour.

So, configuring a firewall rule to block that traffic is probably the best way.

It seems to me that I've configured the rule correctly, and it's on the top, so it should take effect.

What is needed to make it work?

[nambuso-TT]

Hi there

Thanks for the support @KeithFrench 

[KeithFrench]

You should never need to alter the firewall rules unless you have very specific requirements. Why do you need to block DNS traffic to Google DNS anyway? If you are not using these DNS servers by design, then you either have misconfigured your router or a device has static IP addressing utilising Google DNS.