Cisco Cisco Email Security Appliance C160 Mode D'Emploi

You may want to monitor hosts that are connecting to the Cisco appliance to identify the large volume 
senders or to troubleshoot inbound connections to the system. The 

topin

 command provides a snapshot 

of the remote hosts connecting to the system. It displays a table with one row for each remote IP address 
connecting to a specific listener. Two connections from the same IP address to different listeners results 
in 2 rows in the table. 

 describes the fields displayed when using the 

topin

 command.

The system does a reverse DNS lookup to find the remote hostname, and then a forward DNS lookup to 
validate the name. If the forward lookup does not result in the original IP address, or if the reverse DNS 
lookup fails, the table displays the IP address in the hostname column. For more information about the 
process of sender verification, see 

Hostname of the remote host, derived from Reverse DNS lookup.

IP address of the remote host.

Nickname of the listener on the Cisco appliance that is receiving the 
connection.

The number of concurrent connections from the remote host with the 
specified IP address open at the time when the command is run.

mail3.example.com> topin

Status as of:                   Sat Aug 23 21:50:54 2003

#  Remote hostname            Remote IP addr.   listener        Conn. In

1  mail.remotedomain01.com    172.16.0.2        Incoming01            10

2  mail.remotedomain01.com    172.16.0.2        Incoming02            10

3  mail.remotedomain03.com    172.16.0.4        Incoming01             5

4  mail.remotedomain04.com    172.16.0.5        Incoming02             4

5  mail.remotedomain05.com    172.16.0.6        Incoming01             3

6  mail.remotedomain06.com    172.16.0.7        Incoming02             3

7  mail.remotedomain07.com    172.16.0.8        Incoming01             3