Cisco Cisco Email Security Appliance C170 Guia Do Utilizador

To help test and troubleshoot the appliance, you can create a “blackhole” type listener instead of a 
public or private listener. When you create a blackhole listener, you choose whether messages are 
written to disk or not before they are deleted. (See the “Testing and Troubleshooting” chapter for 
more information.) Writing messages to disk before deleting them can help you measure the rate of 
receiving and the speed of the queue. A listener that doesn’t write messages to disk can help you 
measure the pure rate of receiving from your message generation systems. This listener type is only 
available through the 

listenerconfig

 command in the CLI.

 illustrates a typical email gateway configuration created by the System Setup Wizard on 

appliance models that have more than two Ethernet interfaces. Two listeners are created: a public listener 
to serve inbound connections on one interface and a private listener to serve outbound connections on a 
second IP interface. 

 illustrates a typical email gateway configuration created by the System Setup Wizard on 

appliance models that have only two Ethernet interfaces. One public listener on a single IP interface is 
created to serve both inbound and outbound connections.