Which type of router have you tried to connect? Pls. tell us the name of the manufacturer and the type/name of the additional router with the full number of the Firmware.

Moondoggie

When I use an Ethernet cable to connect an additional wireless router to my Speedport Smart router (provided by Telekom), it doesn't work.  I can connect to the additional (added) router, but with no internet connectivity.  The Speedport Smart router doesn't seem to want to provide internet connectivity to any additional router hooked up via Ethernet cable.  Why is this?  Is there a certain configuration that is needed for either router to make this work?

The WAN interface of the additional router needs to be configured either with a fixed IP address belonging to the Speedport's LAN IP-address range (but outside the range of addresses it gives to devices via DHCP) or it needs to be configured to receive it's WAN address via DHCP. Same goes for the default gateway (which should point to the Speedport's LAN address) and the DHCP server.

Did you make such configuraion on your new router? If you don't know how to make the appropriate configuration on the device, please let us know the make and model, maybe someone on the forum has some experience with the device.

And finally, can you elaborate why you want to use a second router at all? Maybe using a second router is not the best choice, sometimes a switch or a WIFI access point or a WIFI mesh repeater are more suitable to the problem.

You simply cannot add another router for additional bandwith (if that is what you've been trying to achieve). The software of an average SpeedPort Smart is not capable of doing this.

Deutsche Telekom have special hybrid routers which are able to combine DSL and LTE . Their current offering is the SpeedPort Pro Plus > https://www.telekom.de/zuhause/geraete-und-zubehoer/wlan-und-router/speedport-pro-plus

Best wishes,

Thomas