How to set pihole as DNS on Arris TG1682G router (Comcast)?

[Night_Thastus]

I finally got my raspberry pi set up. I've got everything I need.

However, now I need to configure the router, and I don't follow how.

I don't see anything directly stating it's related to DNS. The closest thing I think I've found is this:

[Album] imgur.com

I also haven't found anything on setting up a static IP. However, for each connected device I can set either "DHCP" or "Reserved IP" which might be it.

I know that port-forwarding is disabled, "bridge mode" is disabled, DMZ is disabled, UPnP is enabled, Zero Config is disabled, if any of that helps you.

Thanks for any assistance. After $114 I really don't want to hear that I also need to buy a custom router too.

[Tesserax]

@Night_Thastuss
Infinity is not a router brand. Would you please provide the make & model of this router so that we can help you with where the DNS settings would be. Right now, I would suspect that it may be located in the Advanced area.

[Night_Thastus]

@Tesserax

I assumed Comcast set up a unified browser interface for all customers regardless of what specific unit they used. (Or had custom things enabled/disabled)

In any case, it's an Arris TG1682G

[Tesserax]

@Night_Thastus
You can find a copy of the user manual for this router here:

ARRIS XFINITY TG1682 USER MANUAL Pdf Download | ManualsLib

I'll give it a look and see if I can find where you can change the DNS settings.

[EDIT] Well, after reviewing the document at this link and any others that I can find, I found that the user guide to be basically completely useless. It doesn't seem to offer any details on the menu options in the administration interface for this device. Without this information, I'm afraid I won't be able to assist you with where to look to make the DNS changes.

[EDIT, Part Deux] Looks like that this is one of those routers that does NOT allow you to change the DNS settings. In that case, Pi-hole recommends that you enable DHCP service on the Pi-hole to allow you to change the DNS settings to your network clients to use it. I'm not aware of any other workaround, other than getting a different router. Most other routers do not have this issue.

[Night_Thastus]

@Tesserax

I checked myself and didn't see much either.

ADVANCED has the following:

• Port Forwarding
• Port Triggering
• Remote Management
• DMZ
• Device Discovery

[Tesserax]

@Night_Thastus

... and you won't find it. Please see my [EDIT, Part Deux] in my previous reply.

[Night_Thastus]

@Tesserax

Sorry, that was before your edit.

Regarding DHCP, what does this involve?

Will this slow down my internet at all, or cause other complications? Will it work with all the devices on my network regardless of their type?

I'm debating whether to spend another $120+ on a completely new setup rather than mess with this if it's too complicated or prone to complications.

[Tesserax]

@Night_Thastus

Regarding DHCP, what does this involve?

Basically, you enable in on the DHCP tab in Pi-hole. The key is to set the DHCP IP range different than that provided by your Arris router. Better still, if you can disable DHCP on the router, do so and let the Pi-hole provide this service instead.

[jfb]

@Night_Thastus

Will this slow down my internet at all, or cause other complications? Will it work with all the devices on my network regardless of their type?

No slowdown (only a very brief DHCP transaction happens every lease cycle with each client - none of this affects your internet speed: the client is just getting an IP). Yes it will work with your devices.

How do I use Pi-hole's built in DHCP server (and why would I want to)?

Using Your Existing Router For Network-wide Ad Blocking You might not need to use Pi-hole's DHCP server: In many home environments, your router also functions as your DHCP server. In this case, you can often set Pi-hole to be the DNS server for your network clients in the router's DHCP (or LAN) settings page, which allows all of your network clients to block ads simply by connecting to the network. Setting it up this way is also what makes Pi-hole very powerful for network-wide ad blocking. …

[Night_Thastus]

@Tesserax @jfb

Thanks for the information and assistance.

However, I'm still a little confused. Based on the picture I put in the OP, is it possible to disable DHCP on my router? Does that beginning and ending address need to be changed? The tutorial says

Disable the DHCP server on your router (this is a critical step – you will see red warning text when you enable the checkbox )

So it seems I'll need to figure out how to disable it.

If not, how does it work if both the router and the pi are providing this service? Which one "wins"?

[jfb]

If you cannot disable DHCP on the router (they will typically have a checkbox to do this), then change the range of the router DHCP IP addresses to a single IP, and make that the IP of the Pi-Hole. The router will now be distributing a single IP, and Pi-Hole will be using it.

Then, on the Pi-Hole DHCP, set the DHCP range to a non-overlapping range, so it won't duplicate the IP being passed out by the router.

Reboot the router and renew the DHCP lease on all clients and you should be set.

[Night_Thastus]

@jfb

Thanks again. I take it I still need to find a way to make the IP of the pi-hole static for this, right?

Also "renew DHCP lease"? I guess I can set the timer to 1 second, save, and then un-do it?

[Tesserax]

@Night_Thastus

However, I’m still a little confused. Based on the picture I put in the OP, is it possible to disable DHCP on my router? Does that beginning and ending address need to be changed?

My guess is if you scroll up on the screenshot that you provided in your post, you may see the enable/disable DHCP checkbox. @jfb covered the appropriate DHCP range settings to use.

[jfb]

@Night_Thastus

I take it I still need to find a way to make the IP of the pi-hole static for this, right?

Pi-Hole should have set a static IP when it installed. Run this command from the Pi terminal and it will show all the non-commented lines in the specified file. Four of the lines (towards the bottom) should specify the interface, IP, gateway and nameserver.

sudo grep -v '#\|^$' /etc/dhcpcd.conf

A typical configuration for a Pi running on ethernet will look something like this:

interface eth0
    static ip_address=192.168.0.155/24
    static routers=192.168.0.1
    static domain_name_servers=127.0.0.1

[Night_Thastus]

@jfb

Yes, my results are similar to what you showed with that command.

How do I get that nice GUI interface that I saw some of the tutorials show with the checkbox for DHCP for the pihole?

[Night_Thastus]

@Tesserax Unfortunately, there is no such checkbox for the router.

[jfb]

@Night_Thastus

How do I get that nice GUI interface that I saw some of the tutorials show with the checkbox for DHCP for the pihole?

This is on the web admin GUI > settings > DHCP page

[Night_Thastus]

@jfb

I mean, I don't know how to open the GUI in the first place. It's not in the applications on the raspberry pi, at least anywhere I can find. I didn't see an argument I could pass to pihole to make it open either.

[jfb]

The GUI is an option that you select to configure at Pi-Hole install. If you run pihole -r and select "reconfigure", it will ask if you want the web admin installed. Say yes.

You may already have it installed and don't know how to access it. From a browser, type

http://pi.hole/admin

[jfb]

See edit above. You have to open the admin page in a browser.