CISCO PT Simulation Experiment (15) loopback Telnet configuration for routers

CISCO PT Simulation Experiment (15) loopback Telnet configuration for routers

Experimental Purpose :

Mastering the features and functions of router loopback interface

Master the configuration of the Loopback interface to achieve Telnet login to the router

Mastering the basic configuration of RIP dynamic Routing and default routing

Experimental Background :

as the network environment of the company is becoming more and more complex, as a network administrator, it is necessary to allocate the limited network resources (IP address, etc.) rationally, and when the network equipment fails, it can still log on to the device stably, and the configuration loopback interface is especially heavy To.

Technical Principle :

• loopback (Loopback) interface, the most widely used virtual interface, almost all routers can be used, there are many uses, such as configuration device management address, BGP and OSPF's router ID, which depends on its two most significant features:

  • on the router, the loopback interface does not have an actual physical port corresponding to it, and there is no physical link connected to other nodes;

  • As soon as the router is started, the loopback interface will always remain active (up) and will never be affected by network failure and is very stable.

• SVI interface and management of three-layer switches VL The loopback interface of the router has the following features:

  to save Address resources , while avoiding conflicts with other IPs, The interface address specifies a mask of all 1 (255.255.255.255);

  • similar to the SVI interface, it is a three-layer logical interface, but it does not have a MAC address and VLAN ID;

• note:

  • theoretically all interfaces on the router, As long as the configuration of the Vty line can be used for remote logins, but because the loopback interface is always active, the latter is actually more suitable for remote management of routers;

  • In addition to each subnet segment under the local router, the loopback interface IP address can be set to any other address;

• Default route: A special case of static routing. When the packet is looking for the routing table, no route table entry matching the target is found, and if no default route is configured, that is, the router will discard the packet by specifying the router's default next-hop address.

  • Format: Router (config) #ip Route 0.0.0.0 0.0.0.0 [Next hop routed address]

Laboratory Equipment : router-pt 2 units, switch_3560 1 units, switch_2960 1 units, PC 3 units, straight line, crossover line, serial line.

Experimental topology :

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Experimental steps:

New Cisco PT topology diagram

Set IP and gateway addresses for each PC, where the gateway address is the IP address of the routing interface, respectively

Configuration of the three-layer switch Switch1 (VLAN, SVI, routing, etc.)-corresponds to Switch.part1-2

         configuration of Router0 and Router1 (interface IP , clock frequency, etc.)--  router. Part1

Configuring RIP dynamic routing for Switch1, Router0, and Router1- corresponding to Switch.part3 and Router.part2

View Router routing table information (direct-attached routing, dynamic routing) on the

. Part3

Configuring the default route on Switch1- - corresponding SWITCH.PART4

Verifying the connectivity of the loopback interface on the ROUTER0

PC Settings 192.168.1.2//pc0192.168.1.3//pc1//subnet mask and gateway 255.255.255.0192.168.1.1

PC Settings 192.168.2.2//pc2//subnet mask and gateway 255.255.255.0192.168.2.1

/*=part1  s3560 vlan configuration   */switch>enswitch#config tswitch (config) #vlan  2                  //creating VLANs  2switch (Config-vlan) #vlan  3             Create Vlan 3switch (Config-vlan) #exitSwitch (config) #inter  f0/1switch (config-if) #switchport  access  vlan 2       //set Port mode to Accessswitch (config-if) #exitSwitch (config) #inter  f0/2switch (config-if) #switchport  access vlan 3        //set Port mode to Accessswitch (config-if) #exit/*=PART2  SVI routing configuration   */switch (config) #ip   routing             //turn on routing, turn switch off by default ( Config) #interface  vlan 2                   //into the SVI interface mode, the interface automatically opens switch (config-if) #ip  address 192.168.3.1 255.255.255.0          //Configuring the SVI Interface Ipswitch (config-if) #exitSwitch (config) #interface  vlan  3switch (config-if) #ip  address 192.168.1.1 255.255.255.0         switch (config-if) #exit/*=part3  rip Dynamic routing configuration   */switch (config) #router   rip                      //Enter routing configuration mode  -  enable RIP protocol switch (config-router) #version  2                //using version 2, RIPV2 protocol switch (config-router) # network 192.168.1.0     //Specify the network to be advertised (located in the SVI interface) Switch (config-router) #network   192.168.3.0Switch (config) #^zswitch#show ip route/*=part4   default routing configuration   */switch#conf  tswitch (config) #ip route 0.0.0.0 0.0.0.0 192.168.3.2switch (config) #^zswitch#show rswitch#show ip  route

/*=part1  router0  Basic Configuration   */router>enablerouter#conf trouter (config) #inter  f0/0                  //Enter No. 0 module NO. 0 port (Fast Ethernet interface) Router (config-if) #ip  address 192.168.3.2 255.255.255.0     //Configuration F0/0 Interface Iprouter (config-if) #no  shutdown              //open port, default off router (config-if) #exitRouter (config) #interface  serial 2/0        //enters 2nd module NO. 0 port (Serial interface) Router (config-if) #ip  address 10.10.254.1  255.255.255.0    //Configuration S2/0 Interface Iprouter (config-if) #clock  rate 64000         //must be configured with a clock to communicate router (config-if) #no  shutdown              //open port, default off router (config-if) #exit/*=part2   rip Dynamic Routing configuration   */router (conFIG) #router  rip                      //Enter routing configuration mode  -  enable RIP protocol router (config-router) #version  2                //uses version 2, the RIPV2 protocol router ( Config-router) #network  192.168.3.0     //Specifies the network that needs to be advertised (in the routing interface) router (config-router) # Network 10.254.10.0router (config-router) #^zrouter#show ip route/*=part3  loopback interface Configuration   */router#conf trouter (config) #interface  loopback 0          //into routing configuration mode  -  enable RIP protocol router (config-router) #ip  address 192.168.254.1  255.255.255.255     router (Config-router) #^zrouter#show rrouter#show  Ip route

/*=part1  router1  Basic Configuration   */router>enablerouter#conf trouter (config) #inter  f0/0                  //Enter No. 0 module NO. 0 port (Fast Ethernet interface) Router (config-if) #ip  address 192.168.2.1 255.255.255.0     //Configuration F0/0 Interface Iprouter (config-if) #no  shutdown              //open port, default off router (config-if) #exitRouter (config) #interface  serial 2/0        //enters 2nd module NO. 0 port (Serial interface) Router (config-if) #ip  address 10.10.254.2  255.255.255.0    //Configuration S2/0 Interface Iprouter (config-if) #no  shutdown              //open port, default off Router (config) #exit/*=part2   RIP dynamic routing configuration   */router (config) #router  rip                      //into routing configuration mode  -  enable RIP protocol router (config-router) #version  2                //using version 2, That is, the RIPV2 protocol router (config-router) #network  192.168.2.0     //Specifies the network that needs to be advertised (located in the routing interface) router ( Config-router) #network  10.254.10.0router (config-router) #^zrouter#show rrouter#show ip  Route

PC0 (Command prompt cmd) ping 192.168.1.1//ping-pass Gateway Ping 192.168.254.1//ping pass Loopback interface Telnet 192.168.254.1 Remote login//Because no authentication password is set, so log in directly to trying 192.168.254.1 ... Open

Lab environment: Windows 7,cisco PT 7.0

Reference: CCNA Study Guide (7th edition)

CISCO PT Simulation Experiment (15) loopback Telnet configuration for routers