Check the emualator here to find out the truth. :)
http://www.tp-link.com/resources/simulator/Archer_D2/index.htm

emulator seems to accept http://mydomain.ddns.net/ as valid, does not show any errors after i press save.

I have purchased and installed a couple of archer d2 modem/routers, but cant get the vpn connection to work.
Followed instructions properly.
Tried both dns domain and ip address with no success.
Do I have to reboot the routers so they will "detect" each other?

It is better to provide your network topology for furhter look into it.

Follow the guide as below to check your configuration step by step first. Ensure configuration on both matches each other.
http://www.tp-link.com/en/faq-244.html

Hi again,
in order to summarize I am attaching a network topology scheme and a screen capture from one of the modem-routers
I have successfully entered all the options under (network-IPSEC vpn) and on both ends of the connection the IPSec Tunnel Mode Connections shows as "UP"
The only thing I was successful with was installing the F2 network printer on the F1PC1 and printing a test page.
For example I am unable to access the F2 ip webcam from any of the F1 pcs.
How do I access windows shared folders? etc?
Please help!

I am unable to ping from one local network to another

gorfeas wrote

I am unable to ping from one local network to another

Windows Sharing requires all devices to be on a single broadcast domain otherwise you need a properly configured WINS/SAMBA server.

vpnrouter wrote

Windows Sharing requires all devices to be on a single broadcast domain otherwise you need a properly configured WINS/SAMBA server.

forgive my ignorance but I have no idea how to do that.
Do I have to disable dhcp on one of the routers? could you elaborate?
thanks

No, do not disable DHCP. It is too complex if you do not understand the concept of windows file sharing or linux file sharing.
Instead edit your "lmhosts.sam" file located in "%windir%\system32\drivers\etc\"
Create entries for each of your network devices with corresponding ip address and hostname.
Do this for each workstation on both networks.

Example:

192.168.1.1 F1ArcherD2
192.168.1.10 F1PC1
192.168.1.20 F1PC2
192.168.1.30 F1-PRINT-A4
192.168.1.40 F1-IPcam
192.168.2.1 F2ArcherD2
192.168.2.10 F2PC1
192.168.2.20 F2PC2
192.168.2.30 F2-PRINT-A4
192.168.2.40 F2-IPcam

Reboot your workstations. Now you should be able to use windows file sharing by using hostnames instead of ip address.

Hi again, I am trying to revive this thread since I haven't been able to solve my problems.
Alas, it is getting worse. Now the ipsec vpn connection status is always down nomatter what I do (reboot both routers) restart windows etc.
Please let me know if there are any particular steps I should take in order to troubleshoot the situation and make the connection work.
I have tried to setup the connection from scratch but it always shows: down