Cisco Systems PA-E3, PA-2E3 manual Using the loopback Command to Verify the Physical Interface

Checking the Configuration

each signal that is not returned before the specified timeout is displayed as a period (.). A series of exclamation points (!!!!!) indicates a good connection; a series of periods (.....) or the message [timed

out] or [failed] indicates that the connection failed.

Following is an example of a successful ping command to a remote server with the address 10.0.0.0:

router# ping 10.0.0.0 <Return> Type escape sequence to abort.

Sending 5, 100-byte ICMP Echoes to 1.1.1.10, 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 have the correct IP address for the server and that the server is active (powered on), and repeat the ping command. Refer to the publications listed in the “Related Documentation” section on page vi for complete descriptions of interface subcommands and the configuration options available for VIP2-related interfaces, and to determine which subcommands and configuration options support VIP2 functionality.

Using the loopback Command to Verify the Physical Interface

Use the loopback {dte local network {line payload} command to troubleshoot the E3 serial port adapter at the physical interface level. The command loops all packets from the E3 interface either back to the interface or from the network back out toward the network. Use the no form of the command to remove the loop.

The following examples of the loopback {dte local network {line payload} command configure loopback modes on the single interface (interface 0) of a one-port E3 serial port adapter in port adapter slot 0 of a VIP2 in chassis slot 10 of a Cisco 7500 series router:

•Set the interface into loopback data terminal equipment (DTE) mode as follows:

Router# configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

router(config)# interface serial 10/0/0

router(config-if)# loopback dte

Loopback DTE loops the router output data back toward the router (after the line interface unit).

•Set the interface into local loopback mode as follows:

Router# configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

router(config)# interface serial 10/0/0

router(config-if)# loopback local

Local loopback loops the router output data back toward the router at the framer.

•Set the interface into network line loopback mode as follows:

Router# configure terminal

Enter configuration commands, one per line. End with CNTL/Z.

router(config)# interface serial 10/0/0 router(config-if)#loopback network line

Network line loopback loops the data back toward the network (before the framer).

8-20PA-E3 Serial Port Adapter Installation and Configuration