[SOLVED] ASUS RT-AC68U [Merlin firmware] DDNS not working

[Jose Antonio]

Hi,

I am trying to configure DDNS in my router ASUS RT-AC68U with Merlin firmware. My ISP router is working on Bridge mode and my router have a public IP adrress on WAN interface.

When I try to configure DDNS, router display an error saying that it have a private IP adrress on WAN interface, but it's not true.

Anyone cans help me?

Regards.

SOLUTION: Clear NVRAM

 

[Wutikorn]

If your Asus RT-AC68U is getting public IP, I don't know how to fix that. However, I want you to make sure that your router is getting public IP. First go to WebUI(192.168.1.1 is default)-> Login-> look at WAN IP(in network map). Now search in Google "What is my IP?". See if your WAN IP matches IP you get from searching in Google. If not, it is likely that either your ISP modem is not correctly set to bridge mode or your ISP doesn't give you public IP at all.

 

[Jose Antonio]

Thank you for your response.

I look for IP Wan address on nvram and I see that there are two incorrect parameters:

wan0_xipaddr=172.16.0.37
wan0_xgateway=172.16.0.1

It's possible that parameters stay on nvram config after we put ISP router on bridge mode?

Wan IP Addres parameter looks fine, with the correct public IP:

wan_ipaddr=***** (my public ip)

 

[john9527]

wan_ipaddr is only used in some places in the gui. Your actual wan address is in

wan0_ipaddr (and wan1_ipaddr if running dual-wan)

 

[Jose Antonio]

wan0_ipaddr parameter it's correct.

Any idea what's going on?

 

[RMerlin]

Means your ISP must be using CGNAT. Make sure the IP you get is really a public and not a private one.

 

[john9527]

The code checks these ranges

    // test if WAN IP is a private IP.
    var A_class_start = inet_network("10.0.0.0");
    var A_class_end = inet_network("10.255.255.255");
    var B_class_start = inet_network("172.16.0.0");
    var B_class_end = inet_network("172.31.255.255");
    var C_class_start = inet_network("192.168.0.0");
    var C_class_end = inet_network("192.168.255.255");

 

[Jose Antonio]

Thank you for your response. But I am sure that it's a public IP (I am network engineer xD).

I will try to restore NVRAM after work.

 

[Jose Antonio]

SOLVED!!! After clear NVRAM it works fine.