Why Can My Server Be Accessed from the Internet But Cannot Access the Internet?

Symptom

The server can be accessed from, but cannot access the Internet.

Troubleshooting

Check the following possible causes.

Figure 1 Possible causes

Network Configurations

• Firewall

  Disable firewall rules for the ECS and check if Internet connectivity is restored:

  • Linux ECS: Checking the Firewall Configuration.
• NIC

  Check the NIC and DNS configurations.

  • Linux ECS: Checking the NIC Configuration.

Security Group Rules

Check if there is a security group rule for the server denying the outbound traffic.

By default, a security group allows all outbound traffic. If the outbound traffic is denied, you can configure security group rules or click Allow Common Ports.

Network ACL Rules

Check whether the network ACL of the subnet that the server belongs to denies the outbound traffic.

By default, a network ACL denies all outbound traffic. You need to add an outbound rule with Action set to Allow to the network ACL associated with the server.