Issue
A data center and a virtual private cloud (VPC) are connected through an Express Connect. However, ping packets fail to reach the Alibaba Cloud-side and the customer-side IP addresses of the Express Connect circuit.
Possible causes
The inaccessibility may be caused by the following reasons:
No route in the route table of the virtual border router (VBR) points to the Express Connect circuit. After Cloud Enterprise Network (CEN) is activated, the VPC cannot learn routes that point to the Express Connect circuit.
The on-premises gateway device in the data center does not contain a backhaul route that points to the VPC.
The Express Connect circuit is down, and Express Connect fails to establish connections between the data center and VPC.
Solutions
Add a route that points to the Express Connect circuit to the VBR.
Log on to the Express Connect console.
In the top navigation bar, select the region where the VBR is deployed.
In the left-side navigation pane, click Virtual Border Routers (VBRs).
On the Virtual Border Routers (VBRs) page, click the ID of the VBR that you want to manage.
On the Routes tab, click Add Route. In the Add Route panel, set the following parameters and click OK.
Next Hop Type: Select Physical Connection Interface.
Destination CIDR Block: Enter the CIDR block to which the IP address of the Express Connect circuit belongs.
Next Hop: Select the Express Connect circuit that is used to connect the data center and VPC.
Add a backhaul route that points to the VPC to the on-premises gateway device in the data center.
Set the destination CIDR block of the backhaul route to the CIDR block of the VPC or a vSwitch in the VPC, and the next hop to the port of the on-premises gateway device connected to the Express Connect circuit.
Check the port on the on-premises gateway device connected to the Express Connect circuit in the data center. Make sure that the optical port can receive and transmit data and the electrical port is working as expected.
Send ping packets from the on-premises gateway device in the data center to the Alibaba Cloud-side IP address of the Express Connect circuit to test the accessibility.
If an echo reply packet is returned, the data center can communicate with the VPC through the Express Connect circuit.
If no echo reply packet is returned, check for the following issues:
The Express Connect circuit may encounter errors. Contact your Internet service provider (ISP) for troubleshooting.
The router port on the Alibaba Cloud side is not enabled for the Express Connect circuit. Contact Alibaba Cloud technical support.
Applicable scope