Cisco Cisco Email Security Appliance C170 User Guide
30-21
Cisco AsyncOS 8.0.1 for Email User Guide
Chapter 30 Managing and Monitoring Using the CLI
Monitoring Using the CLI
Example
Monitoring Inbound Email Connections
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
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.
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
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
mail3.example.com> hostrate
Recipient host:
[]> aol.com
Enter the number of seconds between displays.
[10]> 1
Time Host CrtCncOut ActvRcp ActvRcp DlvRcp HrdBncRcp SftBncEvt
Status Delta Delta Delta Delta
23:38:23 up 1 0 0 4 0 0
23:38:24 up 1 0 0 4 0 0
23:38:25 up 1 0 0 12 0 0
^C
Table 30-9
Data in the topin Command
Statistic
Description
Remote Hostname
Hostname of the remote host, derived from Reverse DNS lookup.
Remote IP Address
IP address of the remote host.
listener
Nickname of the listener on the Cisco appliance that is receiving the
connection.
connection.
Connections In
The number of concurrent connections from the remote host with the
specified IP address open at the time when the command is run.
specified IP address open at the time when the command is run.