2Wire 3801HGV (In Bridge Mode) + Airport Extreme. Want to use Custom DNS.

I'd like to apply a custom DNS to the Airport Extreme that will be passed to all the devices connected to it.

As you know in order for the Extreme to pass out custom DNS settings it would have to have DHCP enabled.

I recently learned that you can't do this when the Airport Extreme is in Bridge Mode (I also read that you can't enable Guest Wifi).

Those are both correct.

I'd like to change the Airport Extreme out of Bridge mode and let it handle DHCP and DNS.

Any thoughts?

I have two for you:

1. Leave the Extreme in bridge mode. Using the web-based administrator interface on the 2Wire router, add the custom DNS servers so that the 2Wire can provide them to network clients connected to either router.
2. Reconfigure the 2Wire as a bridge. Then reconfigure the Extreme to provide both NAT & DHCP services.

I don't think you can apply custom DNS to the 2Wire router. I have heard it's locked down by AT&T and I haven't come across anything in the configuration UI that would allow me to input my custom DNS.

This may also not allow you to follow the instruction you found to place it into bridge mode too. Hopefully that is not the case.

... and then set the Airport Extreme to do DHCP and NAT (or is it DHCP only?)

With the 2Wire in bridge mode, you will want the Extreme to provide BOTH NAT & DHCP. That would be its default router mode.

Before you dive in, a note of caution that ATT says that there are differences between the 3800 and 3801.

The instructions are for a 3800....and you have a 3801. You might note the user comments at the bottom of the article where the user.....who has a 3801....says that he still gets a Double NAT error.

I think you should expect the same results if you try to configure the AirPort to use DHCP and NAT.

If you were wondering, you cannot configure the AirPort for DHCP only......unless your service provider is giving you a bank of fixed IP addresses. That is very rare these days.

Good luck.

The clear answer with the 3801 is that you are going to have a Double NAT issue with the AirPort router if you try to run the AirPort in Router Mode with DHCP and NAT enabled....whether you use DMZ or not on the 3801.

Using the DMZ is more work, and you do have some sense of accomplishment doing it this way.....but the end result is the same as if you simply connect the AirPort to the 3801 "as is" and then configure the AirPort to enable DHCP and NAT.

I'm not recommending Double NAT....just pointing out that it is an option. Not a good one, but an option.

NAT is what allows you to share a single Public IP address with one or more Private network clients. A "Double NAT" condition is not necessarily a bad thing, but it should be avoided where possible. Basically, being in this condition breaks your network into subnets. The potential problem with that is if you need clients connected to the 2Wire to be able to "see" those connected to the AirPort ... and vice versa. However, all clients regardless of which router they are connected to would still gain Internet access.

So running this in Double NAT is a viable option?

I said that it is an option. Not a good one, but an option.

If you run Double NAT, you will have problems. Among the possibilities are:

Slower browsing (NAT is a firewall, so now you have two firewalls that the signal must negotiate)

You may notice that some Internet sites will load very slowly....or not at all

The AirPort will revert to the correct Bridge Mode setting after a power outage or any firmware updates, so you must manually change the settings back when this occurs

Online gaming consoles will not tolerate Double NAT

I'm sure there are others issues as well

The bottom line.....you won't know how this might work until you try it on your network with your equipment. On a simple home network, you might be able to get away with Double NAT.

Good news that your 3801 is different than my original 3801 and the replacement 3801 that ATT sent......which produced Double NAT errors.

ATT had a guy here for a full day who could not figure it out.

But, glad that you got your issue resolved.

Thanks for the info.

worked for me too. thanks!

After I read this I went out and purchased an Airport Extreme. I was wondering if you wouldnt mind walking me through step by step on how you configured everything. What wire goes where? what settings for the airport extreme and 2wire need to be changed etc...? Im not very tech saavy and help would be greatly appreciated.