I have this device: D-Link DSL-2730U which is an ADSL2+ modem router. It has 1 DSL WAN port, 4 LAN ports.
I have used this for my ADSL broadband, using telephone DSL port and routed the connectivity wirelessly to my other devices like laptops and smartphones.
Now, I left my ADSL broadband, and currently has two other type of Internet connectivity.
Railwire Broadband, which gives me an Ethernet cable, and I can insert directly into my laptop, configure with PPoE username and password, and gets a DHCP assigned IP, gateway, etc., and gets connected to Internet.
Viva Broadband, which again gives me an Ethernet cable, and I can insert directly into my laptop, configure with the static IP, gateway, subnet mask (all provided by my ISP), and gets connected to Internet.
Now, these two types can be routed wirelessly to other devices (laptops / smartphones) using a wireless router (say TPLINK W740N, which has an Ethernet WAN port).
(Note: There is no relation between 1 and 2. These are two types of broadband connectivity offered by my ISPs.)
I need to achieve the same, with D-Link DSL-2730U, as it already has a wireless router inbuilt.
Searched a lot, did some things like turning off DHCP, etc., but, couldn't make it successful. Can someone please put in some light?