Multiple Vnets to OnPermis Connection using site to site VPN

sivaraj86 

Hi 

If you have successfully configured your VPN  

You need to add some routing and security configurations . For that you will need  a Netwotk Virtual Appliance like a Next Gen Firewall ( Fortinet Palo Alto Checkpoint ... ) or use Azure Firewall  . 

I'm assuming you have Hub and Spoke Topology 

So in The Hub you  may have :

• Allow  Traffic to remote virtual network (default )
• Allow Traffic forwarded from remote virtual network (default)
• Use this virtual network's gateway or Route Server (default to none ) 

In Spoke 

• Allow  Traffic to remote virtual network (default )
• Allow Traffic forwarded from remote virtual network (default)
• Use the remote virtual network's gateway or Route Server (default to none ) 

For every spoke  you should

• Create and configure in a route table  a user defined route to  send traffic 0.0.0.0/0 to the private IP of your Firewall  (Next Hop Virtual Appliance ) 

In Hub you need to

• create a route  to each scope with the same next hop  (Firewall)  

Then create Firewall rules to allow or deny traffic for one vnet to another  

For the subnet traffic rely on network security groups / application  security groups attached to subnets instead of nics 

Avoid Overlapping Address