Express Connect circuit FAQ

Can I access different regions after connecting to Alibaba Cloud over an Express Connect circuit?

Yes, you can. A connection over an Express Connect circuit allows your data center to access VPCs in all Alibaba Cloud regions.

Do Express Connect circuits support dynamic routing protocols?

BGP dynamic routing enables traffic forwarding between a data center and a VPC.

Can I connect multiple VPCs using a single Express Connect circuit?

Yes, you can. To do this, reuse the existing virtual border router for the new VPC and create a new router interface on that virtual border router.

What is the maximum number of VPCs that can connect to a single Express Connect circuit?

By default, each virtual border router instance supports six router interfaces. Therefore, when you use Layer 3 router interfaces to connect, you can connect to a maximum of five VPCs.

If a single Express Connect circuit connects to multiple VPCs, is the traffic for each VPC isolated?

You can create VLANs on a leased line to isolate network data. For configuration details about VLAN tags, see Create and manage virtual border routers.

Do Express Connect circuits support NAT?

Alibaba Cloud does not currently support NAT configuration for Express Connect circuits. If you must use NAT for a specific scenario, you must configure NAT in your data center.

What is the relationship between zones and access points?

Zones and access points are both resources within a region. An access point in a region can connect to any zone in the same region.

If your access point and VPC are in different regions, you can connect them using a cross-region Express Connect connection.

My Elastic Compute Service instance is in Zone A. Which access point should I use to connect to this zone?

Zones and access points are both resources within a region. There is no strict one-to-one mapping between them. Access points are deployed at Alibaba Cloud Points of Presence (POPs) within a region. A POP is a network service point. In some regions, POPs and zones are in the same physical location.

How do I enable an Express Connect connection to a VPC in a region outside mainland China?

To enable a cross-border Express Connect connection, you must submit a Letter of Commitment. You can contact your account manager to obtain the letter.

I requested an Express Connect circuit a long time ago. Why is the status still 'Applying'?

After you submit a request for an Express Connect circuit, its status changes to Applying. Our engineers will contact you to review the request within two business days. After the request is approved, the status changes to Approved.

What should I do if the connection to Alibaba Cloud is down?

On the gateway device in your data center, test whether you can reach the Alibaba Cloud IP address from the client IP address of the Express Connect circuit. For example, you can ping the direct connection IP address. If the ping fails, report the issue to your carrier. The demarcation point between Alibaba Cloud and your network is the port on the Alibaba Cloud vSwitch. If this port is down, it indicates an interruption on the carrier's line. You must report this fault to the carrier.

If a fault occurs on the Alibaba Cloud side of the connection, you can submit a ticket to our helpdesk for assistance.

What should I do if the connection speed is slower than expected?

For router interfaces with a bandwidth of less than 1 Gbps, you can use a tool such as iperf to test the bandwidth. If the speed does not exceed 10 Mbps, a port on one side of the connection may be running in half-duplex mode after negotiation. Ask your carrier to change the port mode to automatic rotation.

For router interfaces with a bandwidth greater than 1 Gbps, each data stream is rate-limited to 130 Mbps or 250 Mbps. This is because each data stream has a different payload.