What Is Elastic IP?

Introduction

The Elastic IP (EIP) service enables your cloud resources to communicate with the Internet using static public IP addresses and scalable bandwidths. If a resource has an EIP bound, it can directly access the Internet. If a resource only has a private IP address, it cannot directly access the Internet. An EIP can only be bound to a cloud resource in the same region.

A global Elastic IP (global EIP) can be bound to a global connection bandwidth for private communication and to a global internet bandwidth for Internet access. You can specify a global region and a global EIP pool to assign a global EIP, and bind a global EIP to a cloud instance (such as a load balancer or an ECS) from any region.

You can choose either an EIP or a global EIP as required. For details, see Table 1.

**Table 1** Introduction to EIPs and global EIPs
Item	Where to Use	Function	Advantages	How to Use
EIP	EIPs and cloud resources must be in the same region.	The EIP service provides independent public IP addresses and bandwidth for Internet access. EIPs can be bound to or unbound from ECSs, BMSs, virtual IP addresses, NAT gateways, or load balancers.	An EIP can be flexibly bound to or unbound from a cloud resource in the same region. Low costs Simple networking	Assigning an EIP Binding or Unbinding an EIP
Global EIP	A global EIP with a global connection bandwidth and a global internet bandwidth associated can be bound to a cloud instance in any region.	A global EIP can be bound to a global connection bandwidth for private communication and to a global internet bandwidth for global internet access. You can specify a global region and a global EIP pool to assign a global EIP, and bind a global EIP to an instance (such as an ECS or a load balancer) in any region on the cloud.	Global EIPs can be bound to cloud resources across regions. Global connection bandwidths and global internet bandwidths are required for network communication.	Assigning a Global EIP Binding a Global EIP to an Instance

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EIP

EIPs can be bound to or unbound from ECSs, BMSs, virtual IP addresses, NAT gateways, or load balancers.

Each EIP can be bound to only one cloud resource and both should be in the same region.

Note the following when binding an EIP to an instance (such as ECS):

Each EIP can be bound to only one ECS. If an EIP has been bound to an ECS, it cannot be bound to other cloud resources. You need to unbind the EIP from the ECS before binding it to another cloud resource in the same region.
The EIP and the ECS must be in the same region.

Figure 1 Connecting to the Internet using an EIP
Click to enlarge

EIP Bandwidth

Bandwidth refers to the maximum amount of data that can be transmitted in a given amount of time (generally one second). A larger bandwidth value indicates a stronger transmission capability. Bandwidth is classified into public bandwidth and private bandwidth.

Public bandwidth is the bandwidth consumed when data is transferred between Huawei Cloud and the Internet. Public bandwidth is classified into inbound bandwidth and outbound bandwidth. For details about the outbound bandwidth and inbound bandwidth, see Figure 2.

The metrics about outbound bandwidth on the Cloud Eye console are Outbound Bandwidth and Outbound Traffic.
The metrics about inbound bandwidth on the Cloud Eye console are Inbound Bandwidth and Inbound Traffic.

Figure 2 Inbound bandwidth and outbound bandwidth
Click to enlarge

**Table 2** Inbound bandwidth and outbound bandwidth
Type	Description
Outbound bandwidth	Bandwidth consumed when data is transferred from Huawei Cloud to the Internet. For example, the outbound bandwidth is consumed when ECSs provide services accessible from the Internet or when FTP clients download resources from the ECSs. The metrics about outbound bandwidth on the Cloud Eye console are Outbound Bandwidth and Outbound Traffic. You are only billed for the outbound bandwidth you have used. NOTE: To view the bandwidth usage, see Viewing Metrics. To view bandwidth billing details, see Bills.
Inbound bandwidth	Bandwidth consumed when data is transferred from the Internet to Huawei Cloud. For example, the inbound bandwidth is consumed when downloading resources from the Internet to ECSs and when FTP clients upload resources to the ECSs. The metrics about inbound bandwidth on the Cloud Eye console are Inbound Bandwidth and Inbound Traffic. The maximum inbound bandwidth depends on the size of the outbound bandwidth. If your purchased bandwidth is less than or equal to 10 Mbit/s, the inbound bandwidth will be 10 Mbit/s, and the outbound bandwidth will be the same as the purchased bandwidth. If your purchased bandwidth is greater than 10 Mbit/s, the outbound and inbound bandwidth will be the same as the purchased bandwidth. The preceding bandwidth limit is not applicable in CN North-Beijing1 and CN East-Shanghai2.

EIP Types

EIPs can use dynamic BGP, premium BGP, or static BGP. The following table compares their differences.

**Table 3** Differences among static BGP, dynamic BGP, and premium BGP
Item	Static BGP	Dynamic BGP	Premium BGP
Definition	Static routes are manually configured and must be manually reconfigured anytime when the network topology or link status changes.	Dynamic BGP provides automatic failover and chooses the best path based on the real-time network conditions and preset policies.	Premium BGP chooses the optimal path and ensures low-latency and high-quality networks. BGP is used to interconnect with lines of multiple mainstream carriers. Public network connections that feature low latency and high quality are directly established between the Chinese mainland and Hong Kong (China).
Assurance	When changes occur on a network that uses static BGP, the manual configuration takes some time and high availability cannot be guaranteed. If you select static BGP, your application system must have disaster recovery setups in place.	When a fault occurs on a carrier's link, dynamic BGP will quickly select another optimal path to take over services, ensuring service availability. Currently, carriers in China that support dynamic BGP routing include China Telecom, China Mobile, China Unicom, China Education and Research Network (CERNET), National Radio and Television Administration, and Dr. Peng Group.	Premium BGP has the same assurance capability as that of dynamic BGP. In addition, premium BGP ensures higher network quality and lower latency. Currently, mainstream carriers in Hong Kong (China) are supported.
Advantages	This is a more cost-effective option that allows resources to access the Internet over a single carrier network. The routes can be manually configured.	The BGP public network egress supports switchover across domains within seconds, providing your users with high-speed and secure networks.	Premium BGP chooses the optimal path for access from the abroad. It allows users in the Chinese mainland to access cross-border applications faster.
Service availability	99%	99.95%	99.95%
Billing	Their price from least to most expensive: static BGP, dynamic BGP, and premium BGP. For details, see EIP Pricing Details.

For more information about service availability, see Huawei Cloud Service Level Agreement.
EIPs (excluding those with dynamic BGP) in the CN-Hong Kong and Asia Pacific regions may experience high latency and occasional packet loss when serving clients or accessing public network resources in the Chinese mainland. You are advised to deploy services in the same region or use Cloud Connect for cross-region connection.
Note: Asia Pacific includes AP-Singapore, AP-Bangkok, AP-Jakarta, and AP-Manila.

Accessing EIP

You can access EIPs through the management console or using HTTPS-based APIs.

Management console
Log in to the management console, select Elastic IP from the console homepage, and then perform operations on EIP resources.
APIs
If you need to integrate the EIP service provided by the cloud system into a third-party system for secondary development, you can use an API to access the EIP service. For details, see the Elastic IP API Reference.

Global EIP

A global EIP can be bound to a global connection bandwidth for private communication and to a global internet bandwidth for global internet access. You can specify a global region and a global EIP pool to assign a global EIP, and bind a global EIP to an instance in any region on the cloud. A global EIP architecture is shown in the following figure.

Figure 3 Global EIP architecture
Click to enlarge

Global EIP Communication Scenarios

A global EIP can be bound to a global connection bandwidth for private communication and to a global internet bandwidth for Internet access. To enable an ECS to communicate with the Internet through a global EIP, you also need to bind a global internet gateway to the global EIP.

**Table 4** Global EIP communication scenarios
Communication Scenario	Required Resource	Description	Example	Operation Instruction
Intra-cloud communication	Global EIPs Global connection bandwidths Instances bound to global EIPs, such as ECSs and load balancers	To enable an instance to communicate on the cloud, the global EIP of the instance should have a global connection bandwidth bound. Select a global connection bandwidth type based on the global EIP access point and the region where the instance is located. For details, see Global Connection Bandwidth Overview.	The access point of global EIP-A is CN East-Hangzhou. The load balancer with global EIP-A bound is located in CN East-Shanghai1. CN East-Hangzhou and CN East-Shanghai1 are close to each other and belong to CN East. The type of the global connection bandwidth-A should be Multi-city. The access point of global EIP-B is CN East-Hangzhou. The ECS-B with global EIP-B bound is located in CN South-Guangzhou. CN East-Hangzhou and CN South-Guangzhou are not close to each other but belong to the same geographic region. The type of the global connection bandwidth-B should be Geographic-region. The access point of global EIP-C is CN East-Hangzhou. The ECS-C with global EIP-C bound is located in CN-Hong Kong. CN East-Hangzhou and CN-Hong Kong belong to different geographic regions. The type of the global connection bandwidth-C should be Cross-geographic-region.	Assigning a Global EIP: Assign one or more global EIPs. Binding a Global EIP to an Instance: Bind a global EIP to an instance, such as an ECS or a load balancer. A global EIP can be bound to only one instance from any region at the same time. Adding Instances to a Global Connection Bandwidth: Bind a global EIP to a global connection bandwidth. A global connection bandwidth can only be used by instances of the same type. If you want another type of instances to use a global connection bandwidth that already has instances, you need to remove the instances first.
Internet communication	Global EIPs Global internet bandwidth Instances bound to global EIPs, such as ECSs and load balancers	To enable an instance to communicate with the Internet, the global EIP of the instance should have a global internet bandwidth bound. The global EIP and the global internet bandwidth must have the same access point. Multiple global EIPs can be added to the same global internet bandwidth to reduce costs. For details about global internet bandwidths, see Global Internet Bandwidth Overview.	Global EIP-A, global EIP-B, and global EIP-C are added to global internet bandwidth-A. The global EIPs and the global internet bandwidth must have the same access point, that is, CN East-Hangzhou in this example.	Buying a Global Internet Bandwidth: Choose the same access point for the global EIP and the global internet bandwidth. Adding Global EIPs to a Global Internet Bandwidth: Add global EIPs to a global internet bandwidth. You can add multiple global EIPs to a global internet bandwidth.