Gateway Load Balancer

A Gateway Load Balancer (GWLB) is a powerful tool that helps manage and route traffic through virtual appliances in a cloud environment, such as firewalls, intrusion detection systems, and inspection systems. By using GWLB, organizations can deploy, scale, and manage these virtual appliances efficiently.

Operating at the network layer (Layer 3) of the OSI model, GWLB directs traffic across all IP packets and ports to the designated virtual appliance targets. One key feature of GWLB is flow stickiness, which maintains a consistent flow of traffic to a specific virtual appliance using various tuple configurations (2-tuple, 3-tuple, or 5-tuple). The communication between GWLB and the virtual appliance instances is facilitated through the GENEVE protocol on port 6081.

A unique aspect of GWLB is its combination of a transparent gateway and a load balancer. This setup ensures a single entry and exit point for all network traffic, making it easier to manage and distribute across multiple virtual appliances. As traffic demand increases, GWLB can automatically scale the appliances up, and as demand decreases, it scales them down, ensuring efficient resource utilization without manual intervention.

Another critical component of the GWLB architecture is the Gateway Load Balancer Endpoint. This endpoint facilitates secure traffic exchange across different Virtual Private Clouds (VPCs). It provides private connectivity between the virtual appliances in one VPC (service provider) and application servers in another VPC (service consumer). This ensures that the data flows through the AWS network privately, without exposure to the internet.

GWLB is designed to maximize the availability and reliability of virtual appliances. It performs regular health checks on the instances, rerouting traffic away from any unhealthy appliances to ensure continuous service. This minimizes disruptions and maintains high availability during both planned maintenance and unexpected downtimes.

Organizations can leverage GWLB to centralize and manage their third-party virtual appliances across various VPCs and user accounts, reducing operational overhead while maintaining consistent security and deployment policies. Additionally, GWLB integrates seamlessly with AWS tools like AWS Marketplace and AWS CloudFormation, simplifying the deployment and management of virtual appliances in the cloud. This integration provides a streamlined experience, enabling quick setup and scaling of network functions tailored to organizational needs.