How does an ECS use an EIP?

You can subscribe to an EIP while you subscribe to an ECS. After that, the ECS can access or be accessed by the Internet.

If you do not subscribe to an EIP for an ECS, you can subscribe to an EIP separately and bind the EIP to the ECS in the Console so that the ECS can access or be accessed by the Internet.

After an EIP is bound to an ECS, how to access the ECS externally?

To ensure the security of ECSs, ECSs are added to a security group after they are successfully created. By default, the security group prohibits inward access to the ECSs from the Internet. Therefore, you need to add corresponding inbound rules in the security group so that the ECSs can be accessed from outside.

On the page for setting security group rules, you can select a type from the following options: TCP, UDP, ICMP or All, according to actual conditions.

When an ECS needs to provide services that can be accessed by the Internet and knows the peer IP address or does not need to provide services that can be accessed by the Internet, it is recommended that the source address is set to allow the network segment where the known IP address is located to access the security group according to business requirements.

When the ECS needs to provide services that can be accessed by the Internet and does not know the peer IP address, you are advised to use the default source address 0.0.0.0/0 and then configure ports to improve network security.

You are advised to assign ECSs with different Internet access policies to different security groups.

How many ECSs can use one EIP?

One EIP can be used by only one elastic NIC and one ECS can create multiple elastic NICs. You can determine the number of NICs and whether the NICs are bound to EIPs according to requirements of the ECS.

How can an ECS access the public Network using IPv6?

Configure an IPv6 NIC for the ECS when commissioning the ECS. After the service is enabled, bind IPv6 bandwidth or shared bandwidth to the ECS.

Elastic IP

Operation