Cisco Cisco Email Security Appliance C650 Guía Del Usuario
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Cisco AsyncOS 8.5 for Email User Guide
Chapter 38 Testing and Troubleshooting
Troubleshooting the Network
Troubleshooting
After you have confirmed that the appliance is active on the network, use the following commands to
pinpoint any network problems.
pinpoint any network problems.
•
You can use the
netstat
command to display network connections (both incoming and outgoing),
routing tables, and a number of network interface statistics, including the following information:
–
List of active sockets
–
State of network interfaces
–
Contents of routing tables
–
Size of the listen queues
–
Packet traffic information
•
You can use the
diagnostic -> network -> flush
command to flush all network related caches.
•
You can use the
diagnostic -> network -> arpshow
command to show the system ARP cache.
•
You can use the
packetcapture
command to intercept and display TCP/IP and other packets being
transmitted or received over a network to which the computer is attached.
To use
packetcapture
, set the network interface and the filter. The filter uses the same format the
UNIX
tcpdump
command. Use
start
to begin the packet capture and
stop
to end it. After stopping
the capture, you need to use SCP or FTP to download the files from the
/pub/captures
directory.
For more information, see
.
•
Use the
ping
command to a known working host to confirm that the appliance has an active
connection on the network and is able to reach specific segments of your network.
The
ping
command allows you to test connectivity to a network host from the appliance.
mail3.example.com> ping
Which interface do you want to send the pings from?
1. Auto
2. Management (192.168.42.42/24: mail3.example.com)
3. PrivateNet (192.168.1.1/24: mail3.example.com)
4. PublicNet (192.168.2.1/24: mail3.example.com)
[1]> 1
Please enter the host you wish to ping.
[]> anotherhost.example.com
Press Ctrl-C to stop.
PING anotherhost.example.com (x.x.x.x): 56 data bytes