DDNS not working (RT-AX88U with DSL-AC55U as modem)

[lardayn]

Update:

I've bought a TD-W9960 and set it as modem. In that case, AX~ DDNS still did not work (even my static ip would not bring up the GUI) as planned but however, when i tested my AC~ as a router, it worked. So, I decided to focus on AX~. The thing is, I figured that if I DMZ the router itself (192.168.1.1) everything works.... is that safe?

Hi,

Recently I've bought a RT-AX88U and 'bridged' my DSL-AC55U (which is a combo) to serve as modem-only. Both have latest asuswrt available for them. I've internet connection and clients can connect. However, no DDNS service is working. Plus, my ASUSTOR NAS also having issues, while I can connect to the NAS' UI, the NAS itself cannot connect to WAN (eg EZ Connect & NAS' appstore does not work, and Plex-on-NAS is not reachable even on local LAN). Also, as DSL-AC55U is now in bridge mode, its UI is inaccessible.

Here is my setup:

Before bridging DS-AC55U, I turned off its firewall, DHCP servce etc just to be sure; and than I bridged it, and after restarts, its UI has gone (I guess that's normal). Its former IP address was 192.168.1.1

RT-AX88U is set on PPPoE and its ip is 192.168.1.2 ; the WAN Ethernet from DSL-AC55U's port LAN1 to RT-AX88U works. I got a different and new asuscomm DDNS for the router to avoid conflicts with the (now) modem.

I tried many things, I've changed NAS's DNS addresses, turned off router's firewall, disabled aiprotection, changed router's WAN DNS to Google DNS addresses instead of ISP, changed some cables, let them go through the UPS (you know I was out of options), used an ASUS switch...

I am getting crazy. I did everything I can think about. My IP is static. I get the same ip on router and on what-is-my-ip. So it is not an ISP related double-NAT issue. Plus, DDNS checks on DDNS-search sites return with my ip address.

I wonder if the modem causes double-NAT? But how? It is WAN-bridged not wireless-bridge or PPPoE anymore...

Maybe its my router blocking something?

But then how come NAS is totally stuck within LAN network?

And then why Plex is not running anymore even within LAN area? (Maybe because it cannot reach WAN, and I've Plex Pass, maybe it is trying to validate it and failing cause there's no WAN for NAS?)

Please please please help me.... I'm really stuck here.

Edit:

I've attached 3 screenshots. The last one shows 2 WAN IPs. I do not know why. The first one starting with 78 is my IP. I do not recognize the one starting with 169 (it seems to be a link local ip, why do i have that?) and I've no idea if that's normal. Also, there are 2 gateways.

Edit 2:
Before using my combo as the modem, I wanted to by a standalone-modem but in my country it seems NO ONE sells any standalone-modems. All modems are combos so that's why I decided to use my combo as the VDSL2 modem...

 

[Zetto]

try DDNS on the modem, return it to the regular mode and using AX88 as an access point. If it works, something is screwy with your setup. If not, it's a problem on ISP side. Alternatively, try a different DDNS service or an intermediary like dnsomatic.

 

[lardayn]

Update:

I've bought a TD-W9960 and set it as modem. In that case, AX~ DDNS still did not work (even my static ip would not bring up the GUI) as planned but however, when i tested my AC~ as a router, it worked. So, I decided to focus on AX~. The thing is, I figured that if I DMZ the router itself (192.168.1.1) everything works.... is that safe?

 

[Zetto]

DDNS will have trouble determining internet IP in double-NAT situation, ASUSWRT will tell you so when you try enabling DDNS. I think ASUSWRT Merlin has an option to detect external IP in this situation but you'll have to try it out