Router is the bridge of computer network, is the core device of connecting IP network. It can not only connect different networks, but also choose the path of data transmission, and can block illegal access. Routers are data packet forwarding devices that work in the third layer of the OSI Reference Model-the network layer, and routers implement network interconnection by forwarding packets. For beginners, routers are not easy to configure. This paper takes the hardware Cisco 2800 router used in our hospital as an example to explore the configuration method using console port.
1 Basic functions of routers
1.1 The concept of a router
The so-called "route " refers to the transfer of data from one place to another behavior and action, is a network of multiple network or network equipment, routers in the network layer to achieve network interconnection equipment, routers rely on forwarding network layer packets to achieve network interconnection.
1.2 Basic functions of routers
Simply speaking, routers mainly have the following functions : First, network interconnection, routers support a variety of LAN and WAN interface, mainly for interconnection LAN and WAN, to achieve communication between different networks; second, data processing, providing including packet filtering, packet forwarding, priority, multiplexing, encryption, Compression and firewall functions; Third, network management, routers provide including configuration management, performance management, fault-tolerant management and flow control functions.
2 How routers are configured
Routers can support a variety of ways to configure , this article focuses on the use of console port configuration and its password, interface IP and other related configuration methods, users can choose the appropriate network connection to configure the router: ① use the terminal through the console port for local configuration; ② Remote configuration using asynchronous connection modem, ③ local or remote configuration via Telnet, ④ network configuration via TFTP, ⑤ configuration via Web page.
3 Build Local configuration environment
The following is an introduction to using the console port to build a local configuration environment, which must be configured for routers before using the router, so this article uses the console port to configure the router.
3.1 Router Configuration Interface
There are two configuration ports for routers, console "and" AUX ", and" console "is usually used to connect to the computer through a dedicated connection for the basic configuration of the router, while" AUX "is used for remote configuration connections for routers. A serial port for a microcomputer is connected via a standard RS232 cable and the console port of the router. As shown in Figure 1.
3.2 Configuring terminal parameters
After the cable connection is complete, enter the terminal parameter configuration. First of all, run the terminal simulation program on the computer, with the Windows system with "Super terminal" to establish a new connection, select the actual connection using the microcomputer RS232 serial port, you can set the terminal parameters for routing related configuration.
Basic configuration steps: Click Start--> All Programs--> attachment--> communication--> HyperTerminal, select the serial device for the connection, the system pops up as shown in Figure 2, Figure 3, Figure 4, the connection description interface.
Set Terminal communication parameters are: 9600 baud, 8 bit data bits, 1 bit stop bit, no checksum, no flow control, select terminal emulation type VT100, as shown in Figure 5. Finally, click the OK button to complete the HyperTerminal setup.
3.3 Boot Router
Connect the power, the router will soon be on the terminal screen to see the self-test information, the self-test after the end prompts the user to type carriage return, until a command line prompt "router﹥*****."
Start the Cisco router for the first time and enter the information read mode:
The Cisco Router and Security Device Manager (SDM) are installed on this Device. This
Feature requires the one time use, initial credentials, of username "Cisco"
With password "Cisco".
Please change these publicly known initial credentials through SDM or IOS CLI.
Here ' s the Cisco IOS command:
No username Cisco
Note:please Add a new username to is able to launch SDM for router management.
For more information about SDM/Follow the instructions in the QUICK
START GUIDE for your router or at
4 Configuring Cisco 2800 routers 
4.1 Basic Command mode
Then you can view the running state of the router on the terminal and type "?" Can be online help, such as Router>?;
To perform the current configuration of the router:
router# conf terminal//switch to configuration status
Router (CONF) # enable secret My-root-password//define Super Password
Router (CONF) # IP host ROUTER-SGYY//define router name
Router (conf) # IP Domain-name yourdomain.com//define the owning domain name
Router (CONF) # HTTP Server
router# Show run//display router's current configuration
router# show ip route//Challo by table
router# show IP interface BRI//view connection Status
4.2 Password Configuration
Users can control access to the router by password, and the following is the set access password:
router# Configure terminal
Router (config) # line console 0
Router (config-line) # Login
Router (config-line) # password
Router (config-line) # End
When the password setting is complete, the router logon requires password authentication access when the router is restarted:
Line con 0
Line aux 0
Line vty 0 4
Privilege Level 15
Transport input Telnet
Line Vty 5 15
Privilege Level 15
Transport input Telnet
Scheduler Allocate 20000 1000
4.3 Interface configuration
According to our needs network system requirements, configure the Ethernet network interface  IP address.
To view the status of Ethernet interface 0:
Password: Hu Jintao
router# Show Interface Ethernet 0//shows the status of Ethernet interface 0.
Enter configuration mode information:
Router> enable//into privileged mode
Password://Privileged User password
router# Configure terminal//Enter configuration module
Enter Configuration commands
Router? (config) # interface Ethernet 0//into the external Ethernet port configuration
Router? (config-if) # IP Address
192.168.1.1 255.255.255.0//The IP address of the AUI0 interface is configured to 192.168.1.1, and the subnet mask is 255.255.255.0.
5 Cisco 2800 Router interface configuration information
Cisco 2800 router as a hardware device to build our OA server and network security Policy , configure the Cisco 2800 router interface information as follows:
Building configuration ...
Current configuration:2355 bytes
Service Timestamps Debug DateTime msec
Service Timestamps log datetime msec
No service password-encryption
Logging buffered 51200 warnings
Enable password Hu Jintao
Username Cisco privilege Secret 5 $1$sswy$k0lsljftmyqdif0xtoy05/
Username SGYY privilege Secret 5 $1$UP6R$XTHCUXV.UAJYBQELF3GKE0
No network-clock-participate aim 0
No network-clock-participate aim 1
No AAA New-model
IP domain name yourdomain.com
No Ftp-server write-enable
IP address 192.168.1.1 255.255.255.0
IP nat Inside
IP address 10.1.1.1 255.255.255.0
IP address 18.104.22.168 255.255.255.240
IP Nat Outside
IP Route 0.0.0.0 0.0.0.0 22.214.171.124
IP HTTP Server
IP HTTP Authentication Local
IP nat Pool natout 126.96.36.199 188.8.131.52 netmask 255.255.255.240
IP nat inside source list 1 pool natout overload
IP nat inside source static TCP 192.168.1.10 184.108.40.206 extendable
IP nat inside source static TCP 192.168.2.10 220.127.116.11 8080 extendable
Access-list 1 Permit 192.168.0.0 0.0.255.255
Banner Login ^c
To sum up, the current Cisco2800 router can be correctly run according to the contents of the configuration file. In the actual network management, need to discover, isolate, solve network fault, can use the abundant monitoring and debugging means that the router provides, help us to diagnose and solve the problem that encounters in using the router, the key is to monitor the discovery fault, use the network Test command to locate and isolate the fault.