Barracuda Load Balancer Administrator's Guide - Barracuda Networks

Figure 2.3: Sample Route-Path network layoutDeploying Route-PathIn the Route-Path method of deployment, the Virtual IP addresses must be on the same subnet as theBarracuda Load Balancer. The Real Servers must be on a subnet separate from the VIPs and theBarracuda Load Balancer. This may require changing the IP addresses of your Real Servers.Normally the Real Servers are on an isolated IP network behind the Barracuda Load Balancer. If IPaddress changes are not possible, or if there is no way to make Route-Path deployment work, the nextchoice for deployment method is Direct Server Return. See Direct Server Return on page 22 fordetails.Real Servers that are on multiple networks simultaneously may break the route path. If Real Servershave more than one network adapter enabled, and traffic has a route around the Barracuda LoadBalancer, the deployment will not work properly even though it may appear to work initially. Thereare two exceptions where Real Servers may have multiple network adapters:• The other networks that the Real Servers are on are also isolated and cannot access the WANnetwork without going through the Barracuda Load Balancer• Static routes for incoming and outgoing traffic for each IP address of each Real Server havebeen defined.Each Real Server must be one hop away from the LAN port on the Barracuda Load Balancer. Thismeans their switch must be directly connected into the LAN port of the Barracuda Load Balancer, orconnected to a series of switches that eventually reach the LAN port of the Barracuda Load Balancerwithout going through any other machines.20 Barracuda Load Balancer Administrator’s Guide