Site-to-Site VPN behind DSL Router

Question

Hello, 
 i am facing the situation to build a site to site vpn to our HQ. In the branch office we just have a DSL Connection with DSL Router. 
 The DSL Router get the public ip an is connected to the XG Firewall using a private network like 192.168.1.0/24 
 
 When i initial a site to site configuration i need give the Interface of the local VPN Tunnel start point so that will be my LAN Interface with 
 a private ip from 192.168.1.x network. Will the VPN work ? Cause the 192.168.1.x network will be natted behind the DSL Router. When i would 
 use a RED Device i think its not a problem to place it in the local private network and let it build the connection automatic but i am not sure how 
 that works with the site to site VPN. 
 
 Would be great to get help in that point. The DSL Router we use is a fritzbox 7590. 
 
 Thanks an regards 
 Marco

Keyur · Accepted Answer

Hi marco_47d If you have a dynamic IP, you can configure * in the remote gateway in IPsec VPN policy at Headoffice and Initiate the tunnel from the Branch office. Please also configure Local and Remote ID (IPaddress) at IPsec configuration at HO and BO. HO Local ID: 1.1.1.1 HO Remote ID:2.2.2.2 BO Local ID: 2.2.2.2 BO Remote ID:1.1.1.1

Hayim Caspy · Answer

Site to site and red works similar, just that the red saves you from getting fixed IP in the "red site", and you can you simple router in the "red site" 
 Each site has a different LAN IP, and the site to site or red will route the "other site" IP to be used locally.

carbon15 · Answer

You don't need any dynamic DNS for this type of setup, have the VPN definition at the core to be setup with it's Gateway type to be "Respond only" and the edge site's VPN as "initiate the connection". At the core have the remote gateway address set as "*", use an "ID Type" as a private IP Address (for example) on both ends and matching Pre-Shared key. I use this sort of setup often for 4G sites so it will work for yourself. 
 
 Regards