A TCP Proxy, UDP Proxy, or one of the Layer 7 services makes the Barracuda Load Balancer ADC act as a full proxy. Connections from the client are terminated at the Barracuda Load Balancer ADC, and new connections are established between the Barracuda Load Balancer ADC and the real servers.
You can place the real servers anywhere in your network, as long as they can be routed to by the Barracuda Load Balancer ADC (e.g., via the same subnet, a VLAN, or pre-configured static routes). This can be used in one-armed configurations for applications like Microsoft Exchange Server or Microsoft Lync Server, as well as for custom applications. In two-armed configurations, real servers can access the virtual IP addresses (VIPs) of any TCP Proxy, UDP Proxy, or Layer 7 services that are on the same side of the Barracuda Load Balancer ADC.
There are multiple configuration options available when using one or more TCP Proxy, UDP Proxy, or Layer 7 services:
- Some or all of the real servers are on the same subnet as the LAN.
- Some or all of the real servers are on the same subnet as the WAN.
- Some or all of the real servers are on the same VLAN as the Barracuda Load Balancer ADC.
- Some or all of the real servers are on a different subnet than either the WAN or LAN but are accessible through static routes.
- Some or all of the real servers are on a different subnet and responding to a TCP Proxy, UDP Proxy, or Layer 7 service.
- VIP addresses are on the same subnet as the WAN interface of the Barracuda Load Balancer ADC, and real servers are on a subnet separate from the VIPs.
- VIP addresses are on the same subnet as the LAN interface of the Barracuda Load Balancer ADC, and real servers are on a subnet separate from the VIPs.
Terminology
WAN refers to interfaces configured to access an external network.
LAN refers to interfaces configured to access an internal network.