how to setup 2 router (no bridge) setup for DDNS

[jj.s.taborda]

My current network setup (which works):

A) ISP-provided modem/router (Main): Fiberhome HG180 VDSL w/ voip

Notes:
1) 2 RJ11 ports (1 for DSL and 1 for landline phone)
2) 4 lan ports and NO wan port
3) Connected to internet via PPPoE
4) Internal IP Address is 192.168.254.254
5) NAT and DHCP turned on
6) Only the secondary router is connected to the LAN port
7) Has bridge mode but ISP does not seem to know how I can set it up correctly

B) My own router (Secondary): ASUS RT-AC68U

Notes:
1) Wan port connected to lan port of main router
2) Connected to internet via the main router
3) Internal IP Address is 192.168.1.1 (So different subnet)
4) DHCP turned on and manages the rules/reservation of connected devices
5) Detects double NAT and does not allow DDNS because of this

Needs:
1) I need to be able to access my NAS and RPi on the internet which are connected to
the secondary router. I cant connect them to the main router because of physical and
location issues. And I also want my secondary router to control dhcp as its interface is easier

My issues:
1) My ISP is no help at all as they only know how to configure thier routers based on thier SOP
2) I tried configuring it based on DIFFERENT settings i saw being discussed on forums but its either
i dont know what i'm doing or I cant seem to find the right combination of the recommendations


Hope somebody can help..

 

[Scottray]

Since DHCP is on on both routers, you're getting address conflicts. I think you need to turn off DHCP on the secondary router.

 

[failboat]

I'd suggest putting all your devices on the 2nd router. Only use the first router to pass internet to the 2nd. anything on the first router is going to get blocked by the nat trying to make inbound connections to something on the 2nd.
You can use a switch or AP to get your lan in different areas.

what are your access needs from the outside. software like plex or chrome remote desktop use pinholes. google drive would store it in the cloud. so there are a few options without needing inbound access, which will require complicated setup and has more security risk.

 

[jj.s.taborda]

I'd suggest putting all your devices on the 2nd router. Only use the first router to pass internet to the 2nd. anything on the first router is going to get blocked by the nat trying to make inbound connections to something on the 2nd.
You can use a switch or AP to get your lan in different areas.

what are your access needs from the outside. software like plex or chrome remote desktop use pinholes. google drive would store it in the cloud. so there are a few options without needing inbound access, which will require complicated setup and has more security risk.

All my devices are indeed connected to my second router and I use my first router as my internet gateway. Where do i enable the NAT? main or secondary? how about DHCP? and how do I go about DDNS? What is the correct way to connect both routers together? - as of now, the first router has a lan out to the wan port of the second router and they are on different subnets..

I need to access my plex, pictures, database, home assistant (smart home) controls from the internet..

 

[failboat]

I'd suggest putting all your devices on the 2nd router. Only use the first router to pass internet to the 2nd. anything on the first router is going to get blocked by the nat trying to make inbound connections to something on the 2nd.
You can use a switch or AP to get your lan in different areas.

what are your access needs from the outside. software like plex or chrome remote desktop use pinholes. google drive would store it in the cloud. so there are a few options without needing inbound access, which will require complicated setup and has more security risk.

All my devices are indeed connected to my second router and I use my first router as my internet gateway. Where do i enable the NAT? main or secondary? how about DHCP? and how do I go about DDNS? What is the correct way to connect both routers together? - as of now, the first router has a lan out to the wan port of the second router and they are on different subnets..

I need to access my plex, pictures, database, home assistant (smart home) controls from the internet..

You will have to do some port forwarding twice to make inbound connections.
forward all needed ports to the ip of router 2.
forward ports on router 2 to ip of client.
I'd recommend using fixed leases.

plex works with a pinhole with a capped bandwidth. enable remote access.
most of the smart home stuff works with one too.

https://support.plex.tv/articles/216766168-accessing-a-server-through-relay/

get ip based access working before messing with dns. dns is not needed, you just need to know your public ip address.
you can pay for a domain and have ddns update your public ip for you. which will help if it changes frequently.
It's really not required if you are only opening access for yourself. if you are trying to host a website then you would want one.