Cisco PIX 520 - PIX Firewall 520 Online Help Manual page 60

Tools>Ping
This panel provides a ping tool which is useful for verifying the configuration and operation of a PIX Firewall
unit and surrounding communications links, as well as basic testing of other network devices.
The following sections are included in this Help topic:
Field Descriptions
Using the PDM Ping tool
Troubleshooting operation of the PDM Ping tool
A "ping" is the network equivalent of sonar for submarines. A ping is sent to an IP address and it returns an
"echo". This simple process enables network devices to discover, identify and test each other.
The Ping tool uses the Internet Control Message Protocol (ICMP) protocol described in RFC777 and RFC792.
ICMP defines an echo and echo reply transaction between two network devices, which has become known as a
ping. The echo (request) packet is sent to the IP address of a network device. The receiving device reverses the
source and destination address and sends the packet back as the echo reply.
Field Descriptions
The Ping tool panel has the following fields:
IP Address—The destination IP address for the ICMP echo request packets. Note: Hosts may be assigned
a name by administrators in Hosts/Networks>Basic Information>Host Name and used here in place of
the IP address.
Interface—(Optional). The PIX Firewall interface which will transmit the echo request packets may be
specified. If it is not specified, the PIX Firewall checks the routing table to find the destination address and
uses the required interface.
Ping Output—The result of the ping. When the Ping button is clicked, 3 attempts are made to ping the IP
address and 3 results display the following fields:
Reply IP address/Device name—The IP address of the device pinged or a device name, if
available. The name of the device, if assigned Hosts/Networks, may be displayed, even if NO
response is the result.
Response received/NO response received—
Response received—the result if an echo reply was returned from the destination IP address
specified.
NO response received—the result if no echo reply was returned before the specified timeout.
Response time/timeout (ms)—When the ping is transmitted, a millisecond timer starts with a
specified maximum, or timeout value. This is useful for testing the relative response times of