For example: bru-nas-03# clear countersĬlear "show interface" counters on all interfaces For example: bru-nas-03(config-if)# ip address 172.22.53.1Ĭlear the interface counters using the clear counters command.
#What is a loopback plug serial
If the serial interface above does not have an IP address, obtain a unique address and assign it to the interface with a subnet mask of 255.255.255.0. Use the show running config command to see if the interface has a unique IP address. For example: bru-nas-03(config)# interface serial 0:0īru-nas-03(config-if)# encapsulation HDLC Set the encapsulation for interface serial 0:0 to High-Level Data Link Control (HDLC) in interface configuration mode. Note: This creates a single Serial0:0 interface (where the first 0 stands for the controller and the second 0 represents the channel-group number) using all 31 timeslots for an aggregate of 1.984Mbps.įor more information on performing extended ping tests, refer to Using Extended ping Tests in the Troubleshooting Serial Line Problems document. End with CNTL/Z.īru-nas-02(config-controller)# no pri-group timeslots 1-31īru-nas-02(config-controller)# channel-group 0 timeslots 1-31 bru-nas-02# configure terminalĮnter configuration commands, one per line. If you are not using a channelized E1, proceed to step 4. If the E1 is configured as a PRI you need to remove the pri-group before using the channel-group command. To run the loopback test on channelized E1s (PRI or CAS) we need to use the channel-group E1 controller command to create one or more serial interfaces mapped to a set of timeslots in the channelized E1. Use the write memory command to save your router configuration. Insert the plug into the port in question. Twist the wires from pins 9 and 8 together.Ĭomplete these steps to prepare for the extended ping test: Twist the wires from pins 2 and 15 together. Use wire cutters to cut a working DB-15 cable that is 5 inches long with a connector attached. Creating the Loopback Plug for E1 on DB-15Ĭomplete the following steps to create a loopback plug for E1 on DB-15:
![what is a loopback plug what is a loopback plug](http://cs-electronics.com/wp-content/uploads/2014/12/SCC-10001.jpg)
Refer to the document on RJ-45 cables for more information. With the metal pins facing toward you, and the cable hanging down, pin 1 is the left-most pin.
![what is a loopback plug what is a loopback plug](https://www.inmymobileworld.com/wp-content/uploads/2019/08/20190827_175821.jpg)
The pins on an RJ-45 jack are numbered from 1 through 8. Twist the wires from pins 2 and 5 together. Twist the wires from pins 1 and 4 together. Use wire cutters to cut a working cable that is 5 inches long with a connector attached. Creating the Loopback Plug for E1 on RJ-45Ĭomplete the following steps to create a loopback plug for E1: If you are working in a live network, ensure that you understand the potential impact of any command before using it. All of the devices used in this document started with a cleared (default) configuration. The information presented in this document was created from devices in a specific lab environment.
#What is a loopback plug software
The information in this document is based on the software and hardware versions below.
![what is a loopback plug what is a loopback plug](https://media.fs.com/images/community/wp-content/uploads/2012/11/Loopback-Cable.jpg)
There are no specific prerequisites for this document. Before You Begin Conventionsįor more information on document conventions, see the Cisco Technical Tips Conventions. If a router passes a hardware loopback plug test, then the problem exists elsewhere on the line. The hardware loopback plug test is used to see if the router has any faults.