FAQ about Internet connectivity

Possible cause

Solution

The EIP is not associated with a cloud resource

Check whether the EIP is associated with the resource that you want to access.

• You can log on to the EIP console and view the IP Status of the EIP. If the EIP is in the Allocated state, the EIP is associated with the resource.

• You can call the DescribeEipAddresses operation to query the status of EIPs. If InUse is returned for Status, the EIP is associated with an instance. For more information, see DescribeEipAddresses.

The EIP has expired or has overdue payments

Check whether the EIP has overdue payments.

Alibaba Cloud sends you a text message or an email before and after a payment becomes overdue. We recommend that you renew your EIPs at the earliest opportunity or maintain a sufficient account balance to ensure that your service is not interrupted. For more information, see Overdue payments.

Blocked by security policies on cloud

Check whether the request is blocked by the security policies of the following services:

• Anti-DDoS

  Anti-DDoS Origin Basic automatically sets a scrubbing threshold based on the EIP bandwidth. When traffic reaches the threshold, Anti-DDoS Origin Basic scrubs traffic regardless of whether the traffic is considered service traffic or attack traffic. If the amount of Internet traffic to a cluster exceeds the capacity of Anti-DDoS, the traffic is routed to a blackhole to protect the cluster. In this case, all traffic is blocked. For more information about the EIP scrubbing threshold, see Anti-DDoS Origin Basic.

• Blocked by WAF

  Access fails after your website is connected to Web Application Firewall (WAF). For more information about troubleshooting, see How do I troubleshoot website access exceptions?

• Blocked by Cloud Firewall

  Cloud Firewall provides the Internet firewall feature to detect the data transfer between the Internet and public IP addresses. If Cloud Firewall is enabled for the EIP, requests may be blocked by access control policies. For more information, see Create access control policies for the Internet firewall.

Blocked by security policies of the associated resource

Check whether the request is blocked by the resource associated with the EIP.

For example, if the EIP is associated with an Elastic Compute Service (ECS) instance, requests may be blocked by security rules of the ECS instance. You need to check iptables rules, firewall rules, and third-party security applications of the ECS instance, and check whether the network driver is properly installed.

Blocked by the Internet service provider (ISP)

After you complete the preceding steps, if the EIP still cannot be accessed, another possible cause for EIP access failure is ISP blocking.

You can run an Internet diagnostic on the EIP to check the regions where access to the EIP fails. For more information, see Diagnose an EIP.