This document introduces the main use cases of EIP: Providing public network access capabilities and disaster recovery.
Providing Public Network Access Capabilities
Binding CVM
EIP can be bound to a CVM, providing the CVM with the ability to access and be accessed by the public network.
Binding NAT Gateway
EIP can be bound to a NAT gateway. Through the SNAT and DNAT features of the NAT gateway, multiple CVMs without public IP addresses can access and be accessed by the public network.
Disaster Recovery
In an active-active disaster recovery scenario, applications and resources of the primary and backup CVM are synchronized in real time. The primary CVM is bound to the EIP. When the primary CVM fails, the EIP can be unbound from the primary CVM and rebound to the backup CVM. The public IP used by the business can be smoothly migrated from the failed primary CVM to the backup CVM without modifying the DNS and other mapping relationships, ensuring service continuity.