ELB Cheat Sheet

• There are three Elastic Load Balancers:Network, Application and Classic Load Balancer
• A Elastic Load Balancer must have at least two Availability Zones.
• Elastic Load Balancers cannot go cross-region. You must create one per region.
• ALB has Listeners, Rules and Target Groups to route traffic
• NLB use Listeners and Target Groups to route traffic
• CLB use Listeners and EC2 instances are directly registered as targets to CLB
• Application Load Balancer is for HTTP(S) traffic and the name implies it good for Web Applications
• Network Load Balancer is for TCP/UDP is good for high network throughput eg. Video Games
• Classic Load Balancer is legacy and its recommended to use ALB or NLB
• Use X-Forwarded-For (XFF) to get original IP of incoming traffic passing through ELB
• You can attach Web Application Firewall (WAF) to ALB but not to NLB or CLB
• You can attach Amazon Certification Manager SSL to any of the Elastic Load Balancers for SSL
• ALB has advanced Request Routing rules where you can route based on subdomain header, path and other HTTP(S) information
• Sticky Sessions can be enable for CLB or ALB and sessions are remembered via Cookie