Turning off WiFi on the "modem" does not turn off the DHCP and NAT routing that it is also performing. You have a Frontier / Netgear modem/router.....not a simple modem.
So, you have two devices both trying to act as routers on the network. That creates a Double NAT error, which you do not want.
If you want the Time Capsule to work correctly in DHCP and NAT....then your Frontier / Netgear device needs to be configured as a simple bridge mode modem......not a router as it now is. Whether that is even possible is a question for Frontier / Netgear support.
In my opinion......Apple is just wrong in telling you to ignore the Double NAT error.
Double NAT is an error on the network....that creates issues, as you already know....and choosing to "ignore" it will not make things better.
Sometimes, you have to turn a Double NAT on a network....but that would always be the last option to choose.
Actually, once I switched my TC to DHCP/NAT all my problems with devices ended and connected right away (its been a few days). I have checked my speed with Speedtest app on iphone and it is the same as always. I'm not a gamer, so not sure how that would play out. But my speed is the same.
So the question begs.... Why not just have Apple do DHCP/NAT and tell the horrible (at least for Frontier) ISP to put their Modem/Router in bridge mode???
So if I could put the Netgear in bridge mode, I would be good right?
It sounds like not all Modems allow this thought??
Seems like I want my apple device to be more in control... not the ISP and Netgear modem.
What are you thoughts?
Thanks again for taking time to respond.
You are confusing modem/routers with modems. A modem/router....like you have is a separate modem and a separate router all in the same box that are literally wired together to function as a single device.
Since the device was designed to be a unified modem/router.....most manufacturers do not design devices like this to function as simple modems. (After all, why buy a modem/router and then try to configure it as a modem...when you could simply buy a modem?)
Ask Frontier if they can provide you with a simple modem....not a modem/router. Then, you can configure the Apple to do DHCP and NAT and you will not have a Double NAT error.
As I said, sometimes you have to run a Double NAT on a network, but you would want to avoid it if at all possible. Double NAT can create some unpredictable results. Time will tell if you are able to get away with this error on your network.
Thanks again Bob!
I called Frontier... they refused to show me how to put my modem/router in Bridge mode. Hypothentically, if I did that, would that solve this problem? Sounds like it would. They said they won't show me how to do it because they use PPPoE or something and if I put into bridge mode I won't get internet access. Is that true? They only use bridge mode for businesse they said.
I never wanted a modem/router.... I wish I only had a modem! . Maybe I will call them back and ask only for a modem. Good idea.
Attaching a screen shots below.
If I go into My connection at the top, hit Edit.... no where in there is a bridge option.
If I go to that green Enabled one under VC's... where it says PPPoE, there is a selection to choose Bridge.
But I'm too chicken and I don't know if that is the answer or not.
Thanks again Bob!
Do you know the username and password for the pppoe connection?
If so the best idea is to go and buy your own modem.. they are cheap as chips.. $25 for a basic single port.
TP-Link 8817 is a good one to bridge.
Simply remove the existing modem.. do not change any settings on it and test with the new modem.. if it fails.. put the original one back again.
Also if the current modem has the ability to save the configuration.. then you can make a change.. and if things go bad simply restore the current settings.
But there is nothing wrong with using the TC in bridge.. really.
2. I do know my username and pass to the PPPOE. If I go get a basic modem, how do I get into it to enter that info?
The modem is in bridge.. the PPPOE is done by the TC.. go to the Internet tab and choose pppoe as the connection type.. you can then enter your username and password.
The modem is simply a modem.. ie it converts ethernet to ATM network. Nothing more.
The only thing you need to setup then in the modem is bridge.. with the correct vpi/vci numbers.
You might look at the guidance provided here by someone who is evidently bridging the same device with an AirPort Extreme. As with Frontier's Westell 6100, as I recall, it looks like you set the Protocol to Bridge and then set the Bridge Mode to Bridge. Then turn off DHCP.
The process also looks a bit like the one illustrated here in connection with bridging the Westell VersaLink 7500.