Vnet to Vnet BGP connection

Scope

• Vnet-to-Vnet BGP peering connection.

Prerequsites

• terraform
• azure cli & sign in

1. Clone this repo and change below parameters or keep default. Note: Change these parameters described in later steps: vpngw_bgp_peering_address and vpngw2_bgp_peering_address

variable "resource_group_location" {
  default     = "northeurope"
  description = "Location of the resource group."
}

# --- VPNGW1 ----

variable "vnet1_cidr" {
  default = ["10.4.0.0/16"]
  description = "azure vnet cidr"
}
variable "vnet1_subnet_address" {
  default = ["10.4.1.0/24"]
}
variable "vnet1_gateway_subnet_address" {
  default = ["10.4.3.0/27"]
}
variable "vnet1_bastion_subnet_address" {
  default = ["10.4.4.0/24"]
}
variable "vpngw_bgp_peering_address" {
  default = "10.4.3.30"
  description = "Enter this value after creating vpn gateway, as of now keep default"
}

# --- VPNGW2 ----
variable "vnet2_cidr" {
  default = ["10.6.0.0/16"]
  description = "azure vnet cidr"
}
variable "vnet2_subnet_address" {
  default = ["10.6.1.0/24"]
}
variable "vnet2_gateway_subnet_address" {
  default = ["10.6.3.0/27"]
}
variable "vnet2_bastion_subnet_address" {
  default = ["10.6.4.0/24"]
}
variable "vpngw2_bgp_peering_address" {
  default = "10.6.3.30"
  description = "Enter this value after creating vpn gateway, as of now keep default"
}

1. execute below cmds:

   terraform init
   terraform plan
   terraform apply

Note: If fails, try to execute: terraform init -upgrade on terminal and execute cmd: terraform apply.

3. This is a tricky part somehow terrafrom doesn't allow to import the vpn gateway private ip.

• Copy both the Virtual Network Gateway BGP peer IP address shown in below pic:

• Paste the bgp peer ip in above variables.tf file for parameters:

• • vpngw_bgp_peering_address
• • vpngw2_bgp_peering_address

4. Execute the command in terminal: terraform apply

5. Connect the VM's using bastion host:

   • In global search, Navigate to your Virtual Machines.
   • Click: connect → bastion

6. Open browser enter destination VM private ip.

Links:

• https://learn.microsoft.com/en-us/azure/vpn-gateway/bgp-howto