DSR Load Balance

Direct Server Return Load Balancing

Direct server return load balancing concept

Standard Load Balancing

In standard deployment all traffic goes through load balancer.

Direct Server Return

In direct server return only syn packet is traveling via load balancer. Syn Ack packet goes to client directly.


  • All server must have loopback interface with LB IP address
  • All application on the server listen for connections on LB IP address (lo interface)
  • Firewall - Makes DNAT to forward syn packet to LB
  • LB forward packet to server with LB IP address as destination IP

  • Conslusion

  • Load balancer performance improvement
  • No offloading options
  • No cache options