Overview of Transparent Proxy

Transparent proxy services require browser requests to be routed to the appliance from a network router or switch. This chapter reviews four different router/switch configurations and contains setup instructions for each configuration type.

The four router/switch configurations are:

• An L4 switch
• A WCCP-capable network router
• The appliance's internal routing service, acting as the default gateway for the network subnet being accelerated
• The appliance's internal routing service, acting as an inline (main) network router

Transparent Proxy with an L4 Switch

An L4 switch on the same network as the client workstation intercepts browser requests from the client and sends them to the appliance. The transparent proxy service processes the request for the browser.

How Transparent Proxy Works with an L4 Switch

Figure 10

Benefits of Transparent Proxy with an L4 Switch

Transparent proxy doesn't require browser configuration. After the switch and the appliance are configured, proxy services are transparent to the browser.

For tips and guidelines on setting up transparent proxy services using an L4 switch, see Transparent/L4 Proxy Setup.

Transparent Proxy with a WCCP-Capable Router

A WCCP-capable router, which is configured as the default gateway for the client workstation, intercepts browser requests from the client and routes them to the appliance. The transparent proxy service processes the request for the browser.

How Transparent Proxy Works with a WCCP-Capable Router

Figure 11

Benefits of Transparent Proxy with a WCCP-Capable Router

Transparent proxy doesn't require browser configuration. After the router and the appliance are configured, proxy services are transparent to the browser.

For tips and guidelines on setting up transparent proxy services using WCCP-capable routers, see Transparent/WCCP Proxy Setup.

Transparent Proxy as a Default Gateway (Router)

An appliance's IP address is specified as the default gateway for the client workstation that the browser resides on. The appliance provides both routing and transparent proxy services.

How Transparent Proxy Works as a Default Gateway

Figure 12

Benefits of Transparent Proxy as a Default Gateway

• Transparent proxy doesn't require browser configuration.
• This configuration might be useful for small business networks where the transparent proxy server is on the same subnet as the browsers.
• Using the appliance as a low-cost router might be sufficient for some small businesses.

For tips and guidelines on setting up the appliance as a default gateway and a transparent proxy server, see Transparent/Default Gateway Setup.

Transparent Proxy as an Inline Router (Network Gateway)

An appliance's eth0 IP address is specified as the default gateway for the client workstations that the browsers reside on. The eth1 port connects to the Internet. The appliance provides routing and caching services and serves as the gateway to the Internet.

How Transparent Proxy Works as an Inline Router

Figure 13

Benefits of Transparent Proxy as an Inline Router

• Transparent proxy doesn't require browser configuration.
• This configuration might be useful for small business networks where all the client workstations and the transparent proxy server are on the same network.
• Using the appliance as a low-cost router might be sufficient for some small businesses.

For tips and guidelines on setting up transparent proxy services with the appliance as an inline router, see Transparent/Inline Router Setup.