False commonn knowledge says that a Router behind double NAT can not be used for automatic DDNS. My Asus Router claims so at the DDNS config page. My modem is 192.168.0.1 and assigns via DHCP 192.168.0.100 to my router. My Router is 192.168.1.1 therefore sees WAN address as 192.168.0.100 (instead of atual public WAN address). Therefore, it can not be used maintain my DDNS address. That is the fact.
Here is another fact. My server (NAS) also made by Asus, has DDNS function. NAS is connected to the Switch, which is connected to the Router, which is connected to the modem. When I enter DDNS related pages in my NAS, it will show my real WAN IP address! When I configure it to update my DDNS address at twoDNS.de, it does so perfectly. So, my NAS takes care that my actual WAN adress, othervise visibile only to my modem, is correctly updated for DDNS! Works perfectly. Only downside is: my server check address only every 30 minutes for a change.
btw: noip does not work well and I must renew every month. twoDNS.de works perfectly and I do not have to do anything to keep up the account.
So, if my server can do it, why not my Router?
Here is another fact. My server (NAS) also made by Asus, has DDNS function. NAS is connected to the Switch, which is connected to the Router, which is connected to the modem. When I enter DDNS related pages in my NAS, it will show my real WAN IP address! When I configure it to update my DDNS address at twoDNS.de, it does so perfectly. So, my NAS takes care that my actual WAN adress, othervise visibile only to my modem, is correctly updated for DDNS! Works perfectly. Only downside is: my server check address only every 30 minutes for a change.
btw: noip does not work well and I must renew every month. twoDNS.de works perfectly and I do not have to do anything to keep up the account.
So, if my server can do it, why not my Router?