Where to place the appliance
Use the appliance in transparent router mode to replace an existing router on your network.
TIP:
If you use transparent router mode and you do not replace an existing router, you must
reconfigure part of your network to route traffic correctly through the appliance.
Figure 4: Transparent router mode configuration
You need to:
• Configure your client devices to point to the default gateway.
• Configure the appliance to use the Internet gateway as its default gateway.
• Ensure your client devices can deliver email messages to the mail servers within your
organization.
Explicit proxy mode
In explicit proxy mode, some network devices must be set up explicitly to send traffic to the
appliance. The appliance then works as a proxy or relay, processing traffic on behalf of the
devices.
Explicit proxy mode is best suited to networks where client devices connect to the appliance
through a single upstream and downstream device.
TIP:
This might not be the best option if several network devices must be reconfigured to send
traffic to the appliance.
Network and device configuration
If the appliance is set to explicit proxy mode, you must explicitly configure your internal mail
server to relay email traffic to the appliance. The appliance scans the email traffic before
forwarding it, on behalf of the sender, to the external mail server. The external mail server then
forwards the email message to the recipient.
Pre-installation
Considerations about Network Modes
13
McAfee Email and Web Security Appliance 5.1 Installation Guide
