Hybrid Cloud Primary/Secondary Communication (DC and VPN)

Last updated: 2021-09-09 16:22:35

    If your business is deployed in both a local IDC and a Tencent Cloud VPC, you can connect them via Direct Connect or VPN. To improve the business availability, you set up both DC and VPN connections and configure them as the primary and secondary linkage for redundant communication. This document guides you through how to configure the DC and VPN connection as primary/secondary linkages to connect your IDC to the cloud.

    Note:

    • The route priority feature is currently in beta test. To try it out, please submit a ticket.
    • The next hop type determines the route priority in the VPC route table. By default, the route priority from high to low is CCN, direct connect gateway, VPN gateway, and others.
    • Currently, you cannot adjust the route priority in the console. If needed, please submit a ticket.

    Scenarios

    You have deployed businesses in a Tencent Cloud VPC and an IDC. To interconnect them, you need to configure network connection services for high-availability communications as follows:

    • Direct Connect (primary): connects the local IDC to a VPC-based direct connect gateway through a connection. When the connection linkage is normal, all data traffic between the IDC and the VPC is forwarded through the connection.
    • VPN connection (secondary): establishes an IPsec VPN tunnel to interconnect the local IDC and the Tencent Cloud VPC. When the connection linkage fails, traffic will be forwarded using this linkage to ensure the business availability.

    Prerequisites

    • Your local IDC gateway device should support the IPsec VPN feature and can act as a customer gateway to create a VPN tunnel with the VPN gateway.
    • The IDC gateway device has configured with a static IP address.
    • Sample data and configuration:
      Configuration item Sample value
      Network VPC information Subnet CIDR block 192.168.1.0/24
      Public IP of the VPN gateway 203.xx.xx.82
      IDC information Subnet CIDR block 10.0.1.0/24
      Public IP of the gateway 202.xx.xx.5

    Steps

    Directions

    Step 1: connect IDC to VPC through Direct Connect

    1. Log in to the Direct Connect console and open Dedicated Tunnels and click Connections on the left sidebar to create a connection.
    2. Log in to the VPC console and click Direct Connect Gateway on the left sidebar. Click +New to create a standard direct connect gateway for which the Associate Network is VPC. If the IDC IP range conflicts with the VPC IP range, select the NAT Type.
    3. Go to the Dedicated Tunnels page and click +New to create a dedicated tunnel. Enter the tunnel name, select the connection type and the direct connect gateway instance just created. Configure the IP addresses on both the Tencent Cloud and IDC sides, select the static route, and enter CPE IP range. After the configuration is complete, click Download configuration guide and complete the IDC device configurations as instructed in the guide.
    4. In the route table associated with the VPC subnet for communication, configure a routing policy with the direct connect gateway as the next hop and IDC IP range as the destination.
      Note:

      For detailed configurations, see Getting Started.

    Step 2: connect IDC to VPC through a VPN connection

    1. Log in to the VPN Gateway console and click +New to create a VPN gateway for which the Associate Network is Virtual Private Cloud.
    2. Click Customer Gateway on the left sidebar and click +New to configure a customer gateway (a logical object of the VPN gateway on the IDC side). Enter the public IP address of the VPN gateway on the IDC side, such as 202.xx.xx.5.
    3. Click VPN Tunnel on the left sidebar and click +New to complete configurations such as SPD policy, IKE, and IPsec.
    4. Configure the same VPN tunnel as the step 3 on the local gateway device of the IDC to ensure a normal connection.
    5. In the route table associated with the VPC subnet for communication, configure a routing policy with the VPN gateway as the next hop and IDC IP range as the destination.
      Note:

      For detailed directions, see Connecting VPC to IDC (Route Table).

    Step 3: configure network probes

    Note:

    After the first two steps, there are two VPC routes to IDC. That is, both direct connect gateway and VPN gateway act as the next hop. By default, the direct connect gateway route has a higher priority, making it the primary path and the VPN gateway the secondary path.

    To stay on top of the primary/secondary connection quality, configure two network probes separately to monitor the key metrics such as latency and packet loss rate and check the availability of primary/secondary routes.

    1. Log in to the VPC console.
    2. Click +New to create a network probe. Enter a name and destination IP, select a VPC and subnet, and set the Source Next Hop to direct connect gateway.
    3. Repeat the step 2 and set the Source Next Hop to VPN gateway. After the configuration is complete, you can check the probed network latency and packet loss rate of the direct connect gateway and VPN connection.
      Note:

      For detailed configurations, see Network Probe.

    Step 4: configure an alarm policy

    You can configure an alarm policy for linkages. When a linkage has an exception, alarm notifications are sent to you automatically via emails and SMS message, alerting you of the risks in advance.

    1. Log in to the CM console and go to the Alarm Policy page.
    2. Click Create. Enter the policy name, select VPC/Network Probe for the policy type, specify the network probe instances as the alarm object, and configure trigger conditions, alarm notifications, and other information. Then click Complete.

    Step 5: switch between primary and secondary routes

    After receiving the exception alarms about the direct connect gateway, you need to manually disable the primary route, and forward traffic to the secondary route VPN gateway.

    1. Log in to the VPC console and go to the Route Tables page.
    2. Locate the route table associated with the VPC subnet for communication, click the ID/Name to enter its details page. Click to disable the primary route with the CCN as the next hop. Then the VPC traffic destined to IDC will be forwarded to the VPN gateway, instead of the direct connect gateway.