
4-15
Clear Channel 6-Port T3 (DS3) Line Card Installation and Configuration
OL-3449-02
Chapter4 Configuring the 6T3 Line Card Checking the Configuration
Using the ping Command to Verify Network ConnectivityUsing the ping command, you can verify that an interface port is functioning properly. This section
provides a brief description of this command. Refer to the publications listed in the “Related
Documentation” section on pageviii for detailed command descriptions an d examples.
The ping command sends echo request packets out to a remote device at an IP address that you speci fy.
After sending an echo request, the system waits a specified time for the remote device to reply. Each
echo reply is displayed as an exclamation poi nt (!) o n the co nsole te rm inal ; ea ch r eq ues t t hat is not
returned before the specified timeout is displayed as a period (.). A series of exclamation points (!!!!!)
indicates a good connection; a series of perio ds (.. .. .) o r th e me ssage s [tim ed ou t] o r [fail ed] indi cate a
bad connection.
Following is an example of a successful ping command to a remote server with the address 10.0.0.10:
Router# ping 10.0.0.10 <Return>
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echoes to 10.0.0.10, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/15/64 ms
Router#
If the connection fails, verify that you ha ve the correct IP address for the destination and that the device
is active (powered on), and repeat the ping command.
Proceed to the next section, “Using loopback Commands,” to finish checking network connectivity.
Using loopback CommandsWith the loopback test, you can detect and isolate equipment malfunctions by testing the connection
between the 6T3 line card interface and a remote de vice suc h as a modem o r a CSU/DSU. Th e loopback
command places an interface in loopback mode, which enables test packets that are generated from the
ping command to loop through a remote device or compact s erial cabl e. If the pack ets co mplete the loop,
the connection is good. If not, you can isol ate a fault to the remote device or compact seria l cable in the
path of the loopback test.
Tabl e 4-8 provides examples of the loopback {dte | local | network {line | payload} | remote}
command. The examples given are for interface 0 of a 6T3 line ca rd in slot 2 of a Cisco 7304 router:
Table4-8 Using loopback Commands
Command Function Example
loopback local Sets the interface into local loopback
mode. Local loopback loops the router
output data back toward the router at the
framer.
Router(config)# interface serial 2/0
Router(config-if)# loopback local
loopback network line Sets the interface into network line
loopback mode. Network line loopback
loops the data back toward the network
(before the framer).
Router(config)# interface serial 2/0
Router(config-if)# loopback network
line