Time Capsule Guest Network

The TC is fairly old so really you don't want to change the FIOS gateway for a plain modem.

The guest network is lost on the Gen4 TC (or any airport for that matter) in bridge mode. To get it working again you must use the TC as a router.. ie DHCP and NAT mode. The problem then is you have two NAT routers .. and an error will pop up on the TC that you have double NAT. This is really something you want to avoid.

Nor IMHO do you want to use the old TC as your main router.

What we usually suggest to people is to decide if you want a guest wireless network then use the 2.4ghz on the FIOS router. Change its name and password so only guest users can access it.. or use guest wireless on the Quantum Gateway.. as it is much more recent AC wireless router.

There are other tricky ways around it.. but far too complex from the sounds of your network grasp.

On the Quantum Gateway. Set 2.4ghz to a different name and password to the 5ghz and use this as your guest wireless.

Here is the user guide.

https://www.verizon.com/about/sites/default/files/fios-qgr-userguide140925.pdf

P40 for the settings.

Or you can do it the other way around.. keep the better wireless of the Quantum FIOS for your main wireless and use the weaker TC wireless for your guest.. without changing the operational mode. This is not a true isolated guest wireless but for most situations it is good enough.

Is the problem that our FIOS router is not a "simple router" and we therefore need to get Frontier Communications to provide one for us.....

The Guest Network feature on the Time Capsule and other AirPort routers requires that you have a simple "modem", not a modem/router or gateway device like you have currently.

do I need to change the router mode from Bridge Mode to DHCP and NAT

DHCP and NAT is the correct setting when the Time Capsule is set up to be a router......but that would require that it is connected to a simple modem.......not a modem/router or gateway device like you have now.

It is easy to know if you have simple modem.......since it will have only one Ethernet port.......like the example that you see below:

Unfortunately, Verizon FIOS does not offer this type of modem unless things have changed very recently......so you are locked into a modem/router or gateway device.......which is actually two products in one.......a modem and a router in the same physical package. To operate correctly with a modem/router, the Time Capsule needs to be set up in Off (Bridge Mode), as it is now on your network.

If you attempt to change the Time Capsule from it current "Off (Bridge Mode) setting to DHCP and NAT, the Time Capsule will start blinking amber and display a Double NAT error message.......something that you would want to avoid since that can create any number of issues including slow browsing (or no browsing to some sites), communication problems between devices on the network, and other unforeseen problems.

That being said, sometimes you can get away with a Double NAT error on a simple home network, but I'm not recommending that you try it.

A better plan might be to use the WiFi created by the FIOS router for your "Guest Network" and use the WiFi network created by the Time Capsule as your "Private" network.

The key idea conveyed in both is to use the network that we already see from the FIOS gateway for personal use and the TC network for guests

Or, vice versa. If you are planning to back up to the Time Capsule over WiFi, then things will tend to be more reliable if you use the Time Capsule WiFi for that purpose.

Apple does not officially support backups to a Time Capsule over a third party network, although it "should" work in theory. But, the theory does not always work well in practice, so "should" is not the same as saying "will".

Thanks, but neither LaPastenague nor I have much interest in "points". We are volunteers who donate our time to try to help other users.