Cisco router configuration Basics

Subnet Mask hardware basic Ethernet protocol Network Management

A router is a bridge of a computer network and a core device connecting to an IP network. It can connect different networks, select data transmission routes, and block unauthorized access. Router configuration is not easy for beginners. Take the Cisco router as an example to introduce the general knowledge and configuration of the router for your reference When configuring the router. I. general knowledge about Routers A vro can create a route, execute commands, and use the routing protocol on network interfaces to route data packets. Its hardware is based on interfaces, CPUs, and memory, and the software is based on the network-connected operating system iOS. 1. router interface · A router interface is used to connect a router to a network. It can be divided into two types: LAN interface and WAN interface. The number and type of interfaces vary depending on the vro model. Common interfaces include the following: · High-speed synchronous serial port, which can be connected to DDN, frame relay, X.25, and PSTN (analog telephone line ). · Synchronous/asynchronous serial port, which can be set as synchronous working mode by software. · AuI port, that is, the crude cable port. Generally, an external converter (AUI-RJ45) is required to connect to the 10base-t Ethernet network. · The ISDN port can be connected to the ISDN network (2B + d) and can be used for LAN access to the Internet. · Aux port, which is an asynchronous port. It is mainly used for remote configuration. It can also be used for serial number backup and can be connected to modem. Supports hardware Flow Control (hardware flow ctrol ). · Console port, which is an asynchronous port. It is used to connect a terminal or a computer running a terminal simulation program and configure a local router. Hardware traffic control is not supported. 2. vro CPU Like a PC, a vro has a CPU with a central processing unit, and different routers generally have different CPUs. the CPU is the processing center of a vro. 3. vro memory components The memory is where the router stores information and data. The Cisco router has the following memory components: · Rom (read only memory) · Rom stores the self-check (post: power-on self-test), Bootstrap program, and some or all IOS devices. The ROM in the router is erasable, so IOs can be upgraded. · NVRAM (nonvolatile Random Access Memory) · Non-loss RAM: stores the startup configuration file of the vro. NVRAM can be erased and copied to NVRAM. · Flash Ram · Flash memory is a special Rom that can be erased and programmable. It is used to store other versions of Cisco IOS and is used to upgrade the IOS of the router. · RAM (Random Access Memory) Ram is similar to random memory on a PC. It stores Temporary Information and stores the current route table and configuration information. 4. Router Startup Process ① After power-on, Rom runs the power-on self-check program (post) to check the vro processor, interface, memory and other hardware devices. ② Execute the boot program (bootstrap) in the vro and search for Cisco IOS. IOS in the router can be installed from Rom, Flash Ram, or TFTP server. ③ Search for the configuration file after loading IOS. The configuration file is usually in NVRAM. The configuration file can also be loaded from the TFTP server. ④ After the configuration file is loaded, the related interfaces, protocols, and network parameters are activated. ⑤ When the configuration file cannot be found, the router enters the configuration mode. Ii. router configuration path You can configure a Cisco router in the following ways: 1. Console Connect the serial port of the PC directly to the console of the vrolloconsole through the rolover line, and run the terminal anti-authenticity software on the PC computer to communicate with the vro to complete the configuration of the vro. You can also directly connect the PC to the Auxiliary Port Aux of the router to configure the router. 2. virtual terminal (Telnet) If a vrotelnet has some basic configurations and at least one port is valid (such as an Ethernet port), you can use the computer running the telnet program as the vro's virtual terminal to establish communication with the vro, complete the router configuration. 3. network management workstation Vrouters can be configured through workstation that runs network management software, such as Cisco CiscoWorks and HP OpenView. 4. Cisco configmaker Configmaker is a free router configuration tool developed by Cisco. Configmaker configures the vro in a graphical manner, and then downloads the configuration to the vro through the network. Configmaker requires the vro to run on IOS 11.2 or later. You can use the show version command to view the vro version. 5. TFTP (Trivial File Transfer Protocol) Server TFTP is a simple TCP/IP File Transfer Protocol. It transfers configuration files from the vro to the TFTP server or from the TFTP server to the vro. TFTP does not require a user name or password. It is very easy to use. 3. Three Modes in router configuration Vrouters have three basic access modes: 1. User Exec) The user mode is the default mode when the vro is started. It provides limited access permissions to the vro and allows some non-destructive operations, such as viewing the configuration parameters of the vro and testing the connectivity of the vro, however, you cannot change the vro configuration. In this mode, the prompt (prompt) is "> ". Show interface command to view the router interface information, that is, commands in user mode. 2. Privileged EXEC) The privileged mode, also called enable mode, allows you to perform more operations on a vro. It uses more command sets than the user mode to perform more advanced tests on the vro, for example, run the DEBUG command. In user mode, enable the password to enter the privileged mode. The prompt is "#". Show running-config is a command in privileged mode. 3. Global Configuration) The configuration mode is the highest operating mode of a vro. You can set parameters related to the hardware and software running on the vro, configure interfaces, routing protocols and Wan protocols, and set users and access passwords. Enter the config command at the "#" prompt in privileged mode to enter the configuration mode. Iv. IP Route Configuration You can configure the LAN and WAN interfaces, activate the IP routing protocol, and configure the WAN protocol. The configuration method is as follows: 1. LAN interface configuration A lan interface is a connection point between a router and a LAN. Each LAN interface is connected to a subnet. configuring a LAN interface is to assign an IP address within the subnet address range of the LAN interface to the LAN interface. The configuration method is as follows: ①. In privileged mode, enter the config t command and press enter to enter the vro configuration mode; ②. In configuration mode, enter the name of the interface to be configured, for example, interface Ethernet 0. Press enter and the prompt is changed to config-if; 3. Enter IP address + IP address and subnet mask, for example, IP address 200.38.118.9 255.255.255.0. 4. After the configuration is complete, press Ctrl + Z to exit the configuration and return to the privileged mode. Run the show IP interface E0 command to view the configuration parameters. 2. WAN Interface Configuration The WAN interface is configured in the same way as the LAN interface. The configuration of Serial Port 1 is used as an example. 1. In privileged mode, enter the config t command and press enter to enter the configuration mode; ②. Enter the WAN interface to be configured, for example, serial port 0. The command format is interface serial 0. Press enter to enter the config-If mode; 3. Enter the IP address and subnet mask, and press Enter. 4. Press Ctrl + Z to End Interface Configuration and return the privileged mode. Run the show interface S0 command to view the serial port configuration. 3. Route Protocol Configuration First, determine the routing protocol to choose. Based on the network size and size, the route information protocol rip (Routing Information Protocol) is selected for a small network within 15 hops (from one vro to another ); for large networks, you can select the Internal Gateway Routing Protocol IGRP (interior gateway routing protocol) or Open Shortest Path First (OSPF ). The configuration of various protocols is as follows: 1. Configure the RIP Protocol · Start the rip routing protocol. If you enter router rip in configuration mode, the RIP is determined as the routing protocol. Configure the network directly connected to the vro. In configuration mode, enter the network address. For example, network 139.10.0.0. If different network addresses are connected to the vro, repeat the preceding command. · Configuration allows rip route broadcast in a non-broadcast network. In configuration mode, enter the IP address of the adjacent port of the neighbor router. ②. Configure the IGRP Protocol · Start the IGRP routing protocol. In Configuration Setting Mode, enter the router IGRP and add the autonomous domain number. For example, router IGRP 2. Only routers in the same Autonomous Region can exchange route information. · IGRP transmits route information through the subnet specified by the network in each port. If the subnet is not specified, the router will not broadcast the subnet to other routers. In configuration mode, enter the network and add the subnet number to configure the subnet that participates in the dynamic route. · Specify the IGRP route information that a router knows to broadcast to the routers adjacent to it. IGRP is a broadcast Protocol. To enable IGRP to transmit route information in a non-broadcast network, you must use this setting to allow routers to exchange route information in a non-broadcast network. This option is not required for broadcast networks such as Ethernet. In configuration mode, enter the neighbor and the adjacent port IP address of the neighboring router. ③ Configure the OSPF protocol · Enable the OSPF dynamic routing protocol and enter the router OSPF process number in configuration mode. For example, router OSPF 2. · Define the subnets involved in OSPF. In configuration mode, enter the network IP subnet number wildcard area number. Vro only supports subnet information exchange in the same region, but does not exchange route information between regions. · Specify the network type. In configuration mode, enter the IP address OSPF network broadcast, non-broadcast, or point-to-mutlipoint. Generally, for DDN, frame relay, and X.25 are non-broadcast networks, that is, non-broadcast. · For non-broadcast network connections, the adjacent router of the router must be specified. 4. configuration of common Wan protocols Common Wan protocols include advanced Data Link Control Protocol HDLc, Integrated Service Digital Network ISDN, Point-to-Point Protocol PPP, group Exchange Protocol X.25, and frame-relay. The serial port of the router is connected to the WAN, but the connection to the ISDN must be through the ISDN interface. The Wan Protocol configuration method is as follows: 1. Configure HDLC · The Advanced Data Link Control Protocol (HDLC) is a point-to-point Wan protocol, which is the default Wan protocol for Cisco routers. The configuration method is as follows: · Enter the config t command in privileged mode to enter the configuration mode. · Configure the WAN interface of the connection. For example, interface Serial 1 is used to enter the config-If mode. · HDLC protocol encapsulation. Enter encapsulation HDLC and press Enter. · Set bandwidth. Enter the bandwidth transmission rate [kilobits/second], for example, 56 K, then enter the bandwidth 56. ②. Configure baseband ISDN · ISDN is a digital service carried out using digital technology on existing telephone lines. There are two types of ISDN: BRI (basic rate ISDN) and PRI (Primary Rate ISDN). Bri provides 2B + D channels, and the bandwidth of each B channel is 64 K, channel B is identified by the spid (Service Profile Identifier) number. The configurations of IsDB are different from those of other Wan protocols. · In privileged mode, enter config T and press enter to enter the configuration mode. · Configure the switch type of the ISDN connection. Enter ISDN switch type basic-[Switch identifier]. The switch identifier is the ID of the provider of the connected switch. · Configure the ISDN interface, enter int Bri [number], and number is the bri interface number. · Encapsulate the data into PPP and enter encapsulation PPP. · Configure spid1 and enter ISDN spid1 [spid #]. Spid # The phone number provided by the service provider. · Configure spid2 and enter ISDN spid2 [spid #]. · Ctrl + Z to end the configuration. ③. Configure PPP · In privileged mode, enter the config t command to enter the configuration mode. · Configure the WAN interface. Enter a specific interface number, such as interface serial 0, to enter the config-If mode. · Encapsulate the PPP protocol and enter encapsulation PPP. · Set the bandwidth and enter the bandwidth. · Ctrl + Z to end the configuration. ④ Configure X.25 · In privileged mode, enter config t to enter configuration mode. · Configure the WAN interface. Enter a specific interface number, such as interface serial 0, to enter the config-If mode. · Encapsulate the X.25 protocol and input encapsulation X.25. · Set the bandwidth and enter the bandwidth. · Set the X.25 address of the interface, that is, the x.121 address. Enter the X.25 address X.25 address, for example, X.25 address 8015117011. · Ctrl + Z to end the configuration. ⑤ Configure Frame Relay In privileged mode, enter config t to enter the configuration mode. Configure the WAN interface. Enter a specific interface number, such as interface serial 0, to enter the config-If mode. Encapsulate the frame-relay protocol and input the encapsulation frame. Set the Local Management Interface (LMS) and input the frame-relay LMS-type LMS type. There are several types of LMS: Cisco, ANSI, and q933a, such as frame-relay lm-type ANSI. Set dlci and Enter frame-relay interface-dlci [#] And # As the dlci number. Frame Relay uses a permanent virtual circuit to establish a communication session between the WAN, which is identified by the dlci number. Frame Relay technology provides connection-oriented data link layer communication. Each pair of devices has a defined communication link, and the link has a link ID code dlci (data line connection identifier ). This service is implemented through the Frame Relay virtual circuit, and each frame relay virtual circuit identifies itself with a data link identifier (dlci. The dlci value is generally specified by the Frame Relay Service Provider. Frame Relay supports both PVC and SVC. Set the bandwidth and enter the bandwidth. CTRL + z