> For the complete documentation index, see [llms.txt](https://docs.vngcloud.vn/vng-cloud-document/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.vngcloud.vn/vng-cloud-document/vnetwork/vpn-virtual-private-network-site-to-site.md).

# VPN (Virtual Private Network) Site To Site

## Overview

Default, the VMs are created in a VPC that cannot communicate with a remote private network. Therefore, to access the remote private network from a VPC, the GreenNode private VPN service creates a **Virtual Private Network (VPN) Site-to-Site** and configures routing traffic through this connection. Besides that, this connection is secure connection and safe cause using the **IPSEC** algorithm for authentication and encrypting data at two terminal VPNs local and remote.

Connection Site-to-Site VPN supports connecting with Protocol Internet Protocol security (IPsec).

## Connection between sites

To understand more about the connection between sites, let's take a look at detailed describe

For example, we have 3 network sites, that are Hồ Chí Minh (HCM03), Hà Nội (HAN01), and Private Network (on-premise), each site already setup VPCs

Region HCM03 has VPCs:

* VPC1 (10.1.0.0/16);
* VPC2 (10.2.0.0/16).

Region HAN01 has VPCs:

* VPC1 (172.16.0.0/16);

At Site On-Premise has network:

* 192.168.1.0/24
* 192.168.2.0/24
* 192.168.3.0/24

Create VPN Connections:

* VPNGW-01 of HCM03 <> VPNGW-01 of HAN01;
* VPNGW-01 of HCM03 <> Router of On-Premise;
* VPNGW-02 of HCM03 <> Router of On-Premise.

After finishing create VPN between above connections:

* HCM03 VPC01 includes route 172.16.0.0/16 of HAN01 and 192.168.1.0/24 of On-Premise System.
* HCM03 VPC02 includes route 192.168.1.0/24 and 192.168.2.0/24 of On-Premise System.

<figure><img src="/files/XwmLnKxo2v7nxVcBL1Om" alt=""><figcaption><p>Basic Diagram VPN</p></figcaption></figure>

***

GreenNode provides users VPN service with the below actions:

* [Create VPN Site-to-Site](/vng-cloud-document/vnetwork/vpn-virtual-private-network-site-to-site/create-vpn-site-to-site.md)
* [VPN Connect Condition](/vng-cloud-document/vnetwork/vpn-virtual-private-network-site-to-site/create-vpn-site-to-site/vpn-connect-condition.md)
* [Change VPN Bandwidth](/vng-cloud-document/vnetwork/vpn-virtual-private-network-site-to-site/change-vpn-bandwidth.md)
* [VPN Packages](/vng-cloud-document/vnetwork/vpn-virtual-private-network-site-to-site/vpn-packages.md)
* [Delete VPN](/vng-cloud-document/vnetwork/vpn-virtual-private-network-site-to-site/delete-vpn.md)


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