A direct connect gateway is a traffic entry for Direct Connect that is used to connect Tencent Cloud VPCs with connections (dedicated tunnels). There are two types: VPC-based direct connect gateway and CCN-based direct connect gateway, which are suitable for different use cases.
A standard direct connect gateway supports propagating secondary CIDR blocks. Note the following limits:
As shown in the Direct Connect network architecture, dedicated tunnel mode will affect the destination IP range of the IDC routes to Tencent Cloud VPCs. See the following table for details.
Dedicated Tunnel Mode | IDC Routes to Tencent Cloud |
---|---|
Static | The IDC routes to Tencent Cloud VPCs are configured in the local router. |
BGP | The IDC automatically obtains the VPC CIDR block based on the BGP protocol. |
172.21.0.0/16
).172.21.0.0/16
) obtained by the local router based on the BGP protocol.A CCN-based direct connect gateway can associate one CCN with multiple dedicated tunnels to implement the interconnection between VPCs in the CCN and IDCs. As shown in the Direct Connect network architecture, both the creation time of the direct connect gateway and dedicated tunnel mode will affect the destination IP range of the IDC routes to Tencent Cloud VPCs. See the following table for details.
Creation Time | Dedicated Tunnel Mode | IDC Routes to Tencent Cloud |
---|---|---|
Before 00:00:00 on September 15, 2020 | Static | The IDC routes to Tencent Cloud VPCs are configured in the local router. |
BGP | The IDC automatically obtains the VPC subnet CIDR block based on the BGP protocol. | |
After 00:00:00 on September 15, 2020 | Static | The IDC routes to Tencent Cloud VPCs are configured in the local router. |
BGP | The IDC automatically obtains the VPC CIDR block based on the BGP protocol. |
172.21.0.0/16
) configured in the local router. The direct connect gateways A and B have the same routes and receive local IDC traffic evenly.172.21.0.0/20
, 172.21.16.0/20
), while that synced from the direct connect gateway B is the VPC CIDR block (172.21.0.0/16
). The route with the longest mask will be matched and used for forwarding. Therefore, the local router will forward all traffic to the direct connect gateway A. The traffic will be forwarded to the direct connect gateway B only when the direct connect gateway A fails and loses routes.
Note:For a direct connect gateway created before September 15, 2020, 00:00:00, you can submit a ticket to change its routing policy to VPC CIDR block.
A direct connect gateway is a bridge connecting cloud network and user IDC off the cloud, thus its high availability is critical to stable operation of business.
Tencent’s self-developed Disaggregated Software-Defined Router (DSR) is a new generation of software router system based on SDN, NFV and microservice techniques. It is used to replace classic business routers to avoid single-point failures at the layers of system architecture, routing control and data forwarding. Currently, it is broadly deployed in Tencent’s large-scale, high-performance and highly elastic cloud network system.
Compared to classic network physical devices, DSR supports multiple cloud computing virtualization techniques such as NFV and microservice. It adopts a distributed architecture to effectively prevent overall impact caused by the failure of a single component, so as to discover, isolate and recover from failures at the component level automatically.
Tencent Cloud’s direct connect inherits the high availability feature of DSR to increase the availability of the direct connect gateways significantly.
Was this page helpful?