Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

Only one of the available Ethernet interfaces on the Email Security appliance is required in these 
configurations. However, you can configure two Ethernet interfaces and segregate your internal network 
from your external Internet network connection. 

For more information about assigning multiple IP addresses to the available interfaces, see 

 and 

. 

The Cisco X1070, C670, and C370 Email Security appliances have three available Ethernet interfaces 
by default. The Cisco C170 Email Security appliances have two available Ethernet interfaces. 

In addition to the configurations shown in 

 and 

, you can also configure:

Multiple Email Security appliances using the Centralized Management feature. See 

 

Redundancy at the network interface card level by “teaming” two of the Ethernet interfaces on Email 
Security appliances using the NIC Pairing feature. See 

SMTP and DNS services must have access to the Internet. Other services may also require open firewall 
ports. For details, see 

The typical configuration scenario for the Email Security appliance is as follows: 

Interfaces - Only one of the three available Ethernet interfaces on the Email Security appliance is 
required for most network environments. However, you can configure two Ethernet interfaces and 
segregate your internal network from your external Internet network connection.

Public Listener (incoming email) - The public listener receives connections from many external 
hosts and directs messages to a limited number of internal groupware servers.

Accepts connections from external mail hosts based on settings in the Host Access Table (HAT). 
By default, the HAT is configured to ACCEPT connections from all external mail hosts.

Accepts incoming mail only if it is addressed for the local domains specified in the Recipient 
Access Table (RAT). All other domains are rejected.