how do i set up second router as an extender, seperate SSID, no DHCP,WISP?

[aross1976]

Ok really must admit here that i know nothing about networking
this is my 1st try at any sort of range extension and it is not going well for me at all.

I first tried to install a wifi repeater and it was a total disaster, the repeater used the same SSID and password as the main router with NO option to change that.
I am not sure how such a device could ever even serve any useful purpose at all , because what ended up happening was that my clients would keep on jumping from the extender to the main router whenever the signal from one or the other became more favorable and each time it happened my smart home devices would stop working,specifically wifi devices connected to smartthings.
So the next thing i tried was getting a cheap Tenda N301 router figuring that i could set it up as a repeater or extender with a seperate SSID from my main router but with absolutely no clue on how to do so
I was told to use WISP mode by Tenda support but it was not working out for my needs, which are only for getting 5 esp8266 based wifi devices to connect to smartthings and be stable.
The problem is that with DHCP enabled the devices will connect to the second router but will not work with smartthings at all
and when i switch off DHCP the devices will not even connect to the second router at all
nor will my Android phone, but my PC will still connect to the second router whether or not DHCP is on or off.

So basically want to know how to use the second router as an extender(in WISP mode i guess?)
and keep DHCP on the second router switched to off and still be able to have my clients connect to it
and presumably get their IP from my main router
i must be missing some other steps here to get this working correctly. can anyone help?

 

[Easy Rhino]

I don't know smartthings, so I don't know why the devices break when they roam between the main router and the extender. it doesn't seem like they should do that.

I think your general goal is correct for what you want for your devices.

WISP mode is probably assuming that you have a wireless ISP. and setting up a subnet, which you don't want. you want a repeater on the same network. (although it might work if you disable the DHCP server on the tenda, and set up the rest of the lan parameters so they fit within the network that the main router is administering.).

i'm looking at the tenda user guide:
http://tendacn.com/en/download/detail-3099.html

it sounds like what you want is "Universal Repeater" mode starting on page 33.

however this might force the SSID name to be the same as your main router there. you may or may not be able to change it on the regular Wireless Settings page.