General method for installing and maintaining a Cisco Router

As the core device of network communication, Cisco routers are widely used. The following is my experience in practice:

Control port interface practices and connections

Connect one end of the control cable RJ45 in the Cisco2500/1000 series router accessories to the Cisco CONSOLE port, and the Cisco7000/4000 series router connects one end of the DB25 of the MODEM cable to the Cisco CONSOLE port, one end of DB9 is connected to COMl/2 of the PC. Set the simulation TERMINAL program on the PC: for example, use the TERMINAL program in WINDOWS, use COMl/2, 9600BPS, 8 data bit, 2 stop bit. Others use the default value. After the control port is connected, turn on the power switch of the router.

Initialize Installation

The vro must use a valid power supply. Generally, the zero-ground voltage of the power supply is less than 4 volts, and the zero-fire/ground-fire voltage is 220 volts. Ground Line Protection basically requires that the devices connected to the internet have a ground line, including hosts, workstations, hubs, switches, routers, and MODEM connected To routers. The terminal or PC that configures the router must also use a valid power supply. Cisco synchronous serial interfaces are commonly used. Different interfaces can be obtained through different cables. Such as RS232 and V.35. In addition, the cables of Cisco synchronous serial interface cables are specially pre-fabricated. The system automatically enters the dialog setup status during the first installation. Answer the following questions in sequence: vro name, encrypted super logon password, super logon password, remote logon password, dynamic routing protocol, and interface configuration. Then, answer YES to save the configuration. Wait for 2 minutes and press Enter. Enter the vro name, enter the ENABLE command, and enter the super logon password. The vro name # is displayed #.

Configure synchronous dialing, leased line, and DDN connections

The command line for configuring these items on the vro is as follows:

IPX routing

Interface serial 0 interface serial 0

Ip address l.1.1.1 255.0.0.0 ip address l.1.1.2.

255.0.0.0

Ipx network lll IPX

NETWORK lll

Interface ethernet 0 interface ethernet 0

Ip address 12.1.1.1 255.0.0.0 IPADDRESS 16.1.1.1

255.0.0.0

Ipx network 123456 IPX

NETWORK 12.1TWt) KK 987654

Router igrp 1 ROUTER

IGRP l

NETWORK l.0.0.0 NETWORK l.0.0.0

NETWORK 12.0.0.0 NETWORK

16.0.0.0

Configure X.25 connections

IP ROUTIKG IP

ROUTING

Interface serial 0 interface serial 0

Ip address 1.1.1.1 255.0.0.0 ip address 1.1.1.2

255.0.0.0

ENCAPSULATIO X25 ENCAPSULATION X25

X25 ADDRESS 32699X25 ADDRESS 32688

X25 HTC 16X25 HTC l6

X25 IDLE

6X25 IDLE 6

X25 map ip l.1.1.2 32688 broadcast X25 map ip l.1.1.1

32699 broadcast

Interface ethernet 0 interface ethernet 0

Ip address 12.1.1.1 255.0.0.0 ip address 16.1.1.1 255.0.0.0

Router igrp 1

NETWORK l.0.0.0 NETWORKl.0.0.0

NETWORK l2.0.0.0 NETWORK l6.0.0.0.

Router troubleshooting methods

First, check the status of the MODEM. If the DCD of the MODEM is not on, the connection is faulty. Check the connection first. Check the cable connection of the vro. Connect the control terminal to the vro. Press enter to enter the vro name. Enter show interface serial 0 to view the status of the first line, line, and line protocol. If line is up, DCD signal of the Line Interface received by the router; otherwise, the DCD signal of the line interface is low. If line protocol is up, the line protocol of the line interface is successfully matched. Otherwise, the line Protocol match fails. Hit show interface ethernet 0 if line protocol is up, the line interface is connected normally.

The communication system may have some faults during operation. How to quickly locate the fault and modify it in time is the key to maintaining the normal operation of the system, we will introduce troubleshooting methods for ports, lines, and links.

1. Identify Ethernet port faults:

For the diagnosis of ethernet port faults, we can use the show interface ethernet 0 (for the diagnosis of ethernet port 0) command to check the status of a link, as shown below:

Router # show int ethernet 0

Ethernet 0 is up, line protocol is up

Normal: Ethernet 0 is up, line protocol is up; connection failure. Connect the router to the LAN: Ethernet 0 is up, line protocol is down

Interface failure: Ethernet 0 is down, line protocol is down (disable); interface is artificially disabled: Ethernet 0 is administratively down, line protocol is down (you can remove the shutdown command under interface_mode in the configuration file ). In addition, when we suspect that the port has a physical fault, the shown version is available, and the port with physical faults is not displayed.

2. Identify serial port faults

When the communication with remote communication is interrupted, we should isolate the fault in the following order: from the line to the port to determine whether the line is interrupted: DDN line. View DTU indicators. There are four types of indicators on DTU: Power, Line, DTR, and Ready. After DTU is powered on, the Power lights should be kept on. Line and Ready lights indicate the connection between the DTU and the DDN node host. Under normal circumstances, the two lights should also be on. If any exception is found, contact the DDN Network Management Center in time. DTR lights indicate the connection between DTU and DTE (vro). When the vro is powered on, if the serial port status is normal, the DTR lights on DTU should also be long on (when the line is disconnected, occasionally flash off ). Analog line. Check the indicator lights on the MODEM. For synchronous leased lines, CD, TD, and RD should be kept on long. when data is uploaded and transmitted over the WAN, the TD and RD lights will not stop flashing, when these lights are abnormal, contact the telecommunications department.

3. Determine port faults:

For the diagnosis of serial port faults, we can use the show interface serial 0 (for the diagnosis of serial port 0, the diagnosis of other serial ports is similar) command to check the status of a link, as follows:

Router # show int serial 0

Serial 0 is up, line protocol is up

: Serial 0 is up, line protocol is up indicates normal

: Serial 0 is up, line protocol is down port no physical fault, but the upper layer protocol is not passed (IP, IPX, X25, etc., please check the vro configuration command and check whether the address matches ).

: Serial 0 is down, line protoco1 is down (disable) port has a physical fault, only change the port.

: Serial 0is down, line protocol is down: the carrier/clock signal is sent at the end of the DCE device (MODEN/DTU). Please contact the telecommunications department.

: Serial 0 is administratively down, line protocol is down interface is artificially disabled, you can remove the shutdown command under interface-mode in the configuration status. In addition, when we suspect that the port has a physical fault, the shown version is available, and the port with physical faults is not displayed.