ddns + vpn, but behind nat

[VJ]

Hello,

I'm trying to configure a new router (Asus RT-AC51u) at my parents' place, and wanted to configure it as VPN server.

The configuration is:
Telenet modem/router (DocSis), which does not have DDNS setting, does not support NAT passthrough, but supports DMZ for 1 ip address.
Asus RT-AC51u: connected with WAN port to a LAN port of the modem/router

I cannot enable DDNS on the Asus, as it says I have an invalid IP for DDNS:
-
The wireless router currently uses a private WAN IP address (192.168.x.x, 10,x,x,x, or 172.16.x.x).
This router may be in the multiple-NAT environment and DDNS service cannot work in this environment.
-
And the Asus does not seem to allow the VPN to work if DDNS is not enabled (but I'm not sure on this).


Is there a way around this?
Plan B was to use an old PentiumII for VPN server, using a DDNS client on the PC (some do allow to work behind nat, but I don't know ), but I'm not sure if this works behind double NAT.
I was also thinking if I could use a DDNS client on the PC in combination with the VPN server on the asus. But I don't know if the router's VPN server works without the router's DDNS.

Any suggestions?

Thanks,

Jörg

[VJ]

Ok, just to answer my own question...
VPN works independant of the DDNS service, despite the warning that tells you to switch on DDNS prior to VPN
Here is what I did:
- Asus router in DMZ of modemrouter
- VPN server configured on Asus
- Windows client (HomeBeacon) for my DDNS sevice (ChangeIP) on my father's PC

And it appears to work...!

The old router, a Linksys WRT54GL started acting up, and was no longer giving a reliable connection. I'm thinking of installing DDWRT or Tomato on it, so I can use it as a wireless bridge (perhaps with the different firmware and different functionality it would work), as I also could use a wireless brige with a switch. And it might be better at that than the current old Linksys WET54G).