Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

This appendix describes general rules on networks and IP address assignments, and it presents some 
strategies for connecting the Cisco appliance to your network.

The Cisco X1070, C670, and C370 appliances are equipped with as many as four Ethernet interfaces 
located on the rear panel of the system depending on the configuration (whether or not you have the 
optional optical network interface). They are labeled:

Management

Data1

Data2

Data3

Data4

The Cisco C170 appliance is equipped with two Ethernet interfaces located on the rear panel of the 
system. They are labeled: 

Data1

Data2

When you configure the network, the Cisco appliance must be able to uniquely select an interface to send 
an outgoing packet. This requirement will drive some of the decisions regarding IP address and netmask 
selection for the Ethernet interfaces. The rule is that only one interface can be on a single network (as 
determined through the applications of netmasks to the IP addresses of the interfaces).

An IP address identifies a physical interface on any given network. A physical Ethernet interface can 
have more than one IP address for which it accepts packets. An Ethernet interface that has more than one 
IP address can send packets over that interface with any one of the IP addresses as the source address in 
the packet. This property is used in implementing Virtual Gateway technology.