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Basic Router Lab

1. Building your first network

As your first network lab you are going to | Look on performing basic configurations in network nodes and configuring a network. In detail you will be configure the switch management interface and implement basic connectivity between two user terminals. You are going to learn about basic but useful diagnostic commands for networking.

Figure 1 Basic topo| Logy

Table 1 Addressing table.

DeviceInterfaceIP Address / PrefixDefault Gateway
R1G0/0/0192.168.0.1 /24N/A
2001:db8:acad::1 /64
fe80::1
G0/0/1192.168.1.1 /24
2001:db8:acad:1::1 /64
fe80::1
Loopback010.0.0.1 /24
2001:db8:acad:2::1 /64
fe80::1
PC-ANIC192.168.1.10 /24192.168.1.1
2001:db8:acad:1::10 /64fe80::1
PC-BNIC192.168.0.10 /24192.168.0.1
2001:db8:acad::10 /64fe80::1

Info

Scenario

This is a comprehensive lab to review previously covered IOS router commands. In Parts 1 and 2, you will cable the equipment and complete basic configurations and interface settings on the router.

In Part 3, you will use SSH to connect to the router remotely and utilize the IOS commands to retrieve information from the device to answer questions about the router.

Part 1: Set Up the Topology and Initialise Devices

  1. Cable the network as shown in the topology.

    • Attach the devices as shown in the topology diagram, and cable as necessary.
    • Power on all the devices in the topology.

  2. Initialize and reload the router and switch.

Part 2: Configure Devices and Verify Connectivity

  1. Configure the PC interfaces.

    • Configure the IP address, subnet mask, and default gateway settings on PC-A.

    • Configure the IP address, subnet mask, and default gateway settings on PC-B.

  2. Configure the router

    • Console into the router and enable privileged EXEC mode.

      Terminal

      router> enable

    • Enter configuration mode.

      Terminal

      router# config terminal

    • Assign a device name to the router.

      Terminal

      router(config)# hostname R1

    • Set the router’s domain name as ccna-lab.com.

      Terminal

      R1(config)# ip domain name ccna-lab.com

    • Disable DNS lookup to prevent the router from attempting to translate incorrectly entered commands as though they were host names.

      Terminal

      R1(config)# no ip domain lookup

    • Encrypt the plaintext passwords.

      Terminal

      R1(config)# service password-encryption

    • Configure the system to require a minimum 12-character password.

      Terminal

      R1(config)# security passwords min-length 12

    • Configure the username SSHadmin with an encrypted password of 55Hadm!n2020.

      Terminal

      R1(config)# username SSHadmin secret 55Hadm!n2020

    • Generate a set of crypto keys with a 1024 bit modulus

      Terminal

      R1(config)# crypto key generate rsa

    • Assign the privileged EXEC password to $cisco!PRIV*

      Terminal

      R1(config)# enable secret $cisco!PRIV*

    • Assign $cisco!!CON* as the console password, configure sessions to disconnect after four minutes of inactivity, and enable login.

      Terminal

      R1(config)# line console 0
R1(config-line)# password $cisco!!CON*
R1(config-line)# exec-timeout 4 0
R1(config-line)# login

    • Assign $cisco!!VTY* as the vty password, configure the vty lines to accept SSH connections only, configure sessions to disconnect after four minutes of inactivity, and enable login using the local database.

      Terminal

      R1(config)# line vty 0 4
R1(config-line)# password $cisco!!VTY*
R1(config-line)# exec-timeout 4 0
R1(config-line)# transport input ssh
R1(config-line)# login local

    • Create a banner that warns anyone accessing the device that unauthorized access is prohibited.

      Terminal

      R1(config)# banner motd $ Authorized Users Only! $

    • Enable IPv6 Routing

      Terminal

      R1(config)# ipv6 unicast-routing

    • Configure all three interfaces on the router with the IPv4 and IPv6 addressing information from the addressing table above. Configure all three interfaces with descriptions. Activate all three interfaces.

      Terminal

      R1(config)# interface g0/0/0
R1(config-if)# ip address 192.168.0.1 255.255.255.0
R1(config-if)# ipv6 address fe80::1 link-local
R1(config-if)# ipv6 address 2001:db8:acad::1/64
R1(config-if)# description Connection to PC-B
R1(config-if)# no shutdown
R1(config-if)# exit
R1(config)# interface g0/0/1
R1(config-if)# ip address 192.168.1.1 255.255.255.0
R1(config-if)# ipv6 address fe80::1 link-local
R1(config-if)# ipv6 address 2001:db8:acad:1::1/64
R1(config-if)# description Connection to S1
R1(config-if)# no shutdown
R1(config-if)# exit
R1(config)# interface loopback0
R1(config-if)# ip address 10.0.0.1 255.255.255.0
R1(config-if)# ipv6 address fe80::1 link-local
R1(config-if)# ipv6 address 2001:db8:acad:2::1/64
R1(config-if)# description loopback adapter
R1(config-if)# no shutdown
R1(config-if)# exit

    • The router should not allow vty logins for two minutes if three failed login attempts occur within 60 seconds.

      Terminal

      R1(config)# login block-for 120 attempts 3 within 60
R1(config)# exit

    • Set the clock on the router.

      Terminal

      R1# clock set 15:20:00 5 Jan 2024

    • Save the running configuration to the startup configuration file.

      Terminal

      R1# copy running-config startup-config

  3. What would be the result of reloading the router prior to completing the copy running-config startup-config command?
    • The contents of the running configuration in RAM would be erased during reload. As a result, the router would boot up without a startup configuration and the user would be asked if they would like to enter initial configuration dialog.

  4. Verify network connectivity.

    • Using the command line at PC-A, ping the IPv4 and IPv6 addresses for PC-B.

    Info

    • It may be necessary to disable the PCs firewall.

  5. Remotely access R1 from PC-A using the Tera Term SSH client.

    • Using Tera Term on PC-A, open an SSH session to the R1 Loopback interface IPv4 address. Ensure that the SSH radio button is selected and then click OK to connect to the router. Log in as SSHadmin with the password 55Hadm!n2020.

  6. Using Tera Term on PC-A, open an SSH session to the R1 Loopback interface IPv6 address.

    • Ensure that the SSH radio button is selected and then click OK to connect to the router.
    • Log in as SSHadmin with the password 55Hadm!n2020.

    Info

    • The IPv6 address should be surrounded with square brackets, i.e. [IPv6 address]

  7. Why is the Telnet protocol considered to be a security risk?

    A Telnet session can be seen in plaintext. It is not encrypted. Passwords can easily be seen using a packet sniffer.

Part 3: Display Router Information

In Part 3, you will use show commands from an SSH session to retrieve information from the router.

Establish an SSH session to R1.

  1. Using Tera Term on PC-B, open an SSH session to the R1 Loopback interface IPv6 address and log in as SSHadmin with the password 55Hadm!n2020.

Retrieve important hardware and software information.

  1. Use the show version command to answer questions about the route

    Terminal

    R1# show version

  2. What is the name of the IOS image that the router is running?

    Image version may vary: bootflash:/isr4300-universalk9.03.16.05.S.155-3.S5-ext.SPA.bin

  1. How much non-volatile random-access memory (NVRAM) does the router have?

    Answers may vary: 32768K bytes of NVRAM

  1. How much Flash memory does the router have?

    Answers may vary: 3223551K bytes of flash memory

  1. The show commands often provide multiple screens of outputs. Filtering the output allows a user to display certain sections of the output. To enable the filtering command, enter a pipe (|) character after a show command, followed by a filtering parameter and a filtering expression. You can match the output to the filtering statement by using the include keyword to display all lines from the output that contain the filtering expression. Filter the show version command, using show version | include register to answer the following question:

    • What is the boot process for the router on the next reload?

      • Answers may vary. In most cases (0x2102), the router will undergo a normal boot, load the IOS from the Flash memory, and load the startup configuration from the NVRAM if present. If the config register is 0x2142, the router will bypass the startup config and begin at the user-mode command prompt. If the initial boot fails, the router goes into ROMMON mode.

        R1# show version | include register
Configuration register is 0x2142 (will be 0x2102 at next reload)

  2. Display the start up configuration using show startup-config

    Hidden for ease of viewing...

     
    R1# show start
Using 1997 out of 33554432 bytes
!
! Last configuration change at 15:20:18 UTC Thu Sep 5 2019
! NVRAM config last updated at 15:25:17 UTC Thu Sep 5 2019
!
version 16.9
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
platform qfp utilization monitor load 80
no platform punt-keepalive disable-kernel-core
!
hostname R1
!
boot-start-marker
boot-end-marker
!
security passwords min-length 12
enable secret 5 $1$b2iA$/7Hj3HRmBXTbOESxm1yiG0
!
no aaa new-model
!
no ip domain lookup
ip domain name ccna-lab.com
!
login block-for 120 attempts 3 within 60
login on-success log
!
subscriber templating
!
ipv6 unicast-routing
multilink bundle-name authenticated
!
license udi pid ISR4221/K9 sn FGL221693BV
no license smart enable
diagnostic bootup level minimal
!
spanning-tree extend system-id
!
username SSHadmin secret 5 $1$6HtR$T0QPZWbzp6bz3g6iwmZrP1
!
redundancy
mode none
!
interface Loopback0
description loopback adapter
ip address 10.0.0.1 255.255.255.0
ipv6 address FE80::1 link-local
ipv6 address 2001:DB8:ACAD:2::1/64
!
interface GigabitEthernet0/0/0
description Connection to PC-B
ip address 192.168.0.1 255.255.255.0
negotiation auto
ipv6 address FE80::1 link-local
ipv6 address 2001:DB8:ACAD::1/64
!
interface GigabitEthernet0/0/1
description Connection to S1
ip address 192.168.1.1 255.255.255.0
negotiation auto
ipv6 address FE80::1 link-local
ipv6 address 2001:DB8:ACAD:1::1/64
!
interface Serial0/1/0
no ip address
!
interface Serial0/1/1
no ip address
!
ip forward-protocol nd
no ip http server
ip http secure-server
!
control-plane
!
banner motd ^C Authorized Users Only! ^C
!
line con 0
exec-timeout 4 0
password 7 145311021F07256A650B1C1B68
logging synchronous
login
transport input none
stopbits 1
line aux 0
stopbits 1
line vty 0 4
exec-timeout 4 0
password 7 15560805172924656905011B59
login local
transport input ssh
!
end

  1. How are passwords presented in the output?

    • Passwords are encrypted due to the service password-encryption command.

    • Use the show startup-config | section vty command.

      R1# show startup-config | section vty
line vty 0 4
exec-timeout 4 0
password 7 15560805172924656905011B59
login local
transport input ssh

  2. Display the routing table on the router using the show ip route command on the router to answer the following questions:

    Hidden for ease of viewing...

     
    R1# show ip route
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2
    i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
    ia - IS-IS inter area, * - candidate default, U - per-user static route
    o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
    a - application route
    + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

    10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        10.0.0.0/24 is directly connected, Loopback0
L        10.0.0.1/32 is directly connected, Loopback0
    192.168.0.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.0.0/24 is directly connected, GigabitEthernet0/0/0
L        192.168.0.1/32 is directly connected, GigabitEthernet0/0/0
    192.168.1.0/24 is variably subnetted, 2 subnets, 2 masks
C        192.168.1.0/24 is directly connected, GigabitEthernet0/0/1
L        192.168.1.1/32 is directly connected, GigabitEthernet0/0/1

  1. What code is used in the routing table to indicate a directly connected network?
    • The C designates a directly connected subnet.
    • An L designates a local interface.
    • Both answers are correct

  1. How many route entries are coded with a C code in the routing table?
    • 3

  2. Display a summary list of the interfaces on the router using the show ip interface brief command on the router to answer the following question:

    Terminal

    R1# show ip interface brief
Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet0/0/0   192.168.0.1     YES manual up                    up
GigabitEthernet0/0/1   192.168.1.1     YES manual up                    up
Serial0/1/0            unassigned      YES unset  up                    up
Serial0/1/1            unassigned      YES unset  up                    up
Loopback0              10.0.0.1        YES manual up                    up

  3. What command changed the status of the Gigabit Ethernet ports from administratively down to up?

     
    no shutdown

  4. Use the show ipv6 int brief command to verify IPv6 settings on R1.

    Terminal

    R1# show ipv6 interface brief
GigabitEthernet0/0/0   [up/up]
    FE80::1
    2001:DB8:ACAD::1
GigabitEthernet0/0/1   [up/up]
    FE80::1
    2001:DB8:ACAD:1::1
Serial0/1/0            [up/up]
    unassigned
Serial0/1/1            [up/up]
    unassigned
Loopback0              [up/up]
    FE80::1
    2001:DB8:ACAD:2::1

  5. What is the meaning of the [up/up] part of the output?

    The [up/up] status reflects the Layer 1 and Layer 2 status of the interface and does not rely on Layer 3 for status.

  1. On PC-B, change its configuration so that it no longer has a static IPv6 address. You may have to reboot the machine. Then, issue the ipconfig command on PC-B to examine the IPv6 configuration.

  1. What is the IPv6 address assigned to PC-B?
    • Answers will vary. IPv6 address of 2001:db8:acad:d428:7de2:997c:b05a

  1. What is the default gateway assigned to PC-B?

     
    fe80::1

Part 4: Reflection Questions

  1. In researching a network connectivity issue, a technician suspects that an interface was not enabled.

    What show command could the technician use to troubleshoot this issue?

    Answers may vary. However, show ip interface brief or show interfaces or show startup-config would provide the information.

  1. In researching a network connectivity issue, a technician suspects that an interface was assigned an incorrect subnet mask.

    What show command could the technician use to troubleshoot this issue?

    Answers may vary. show startup-config or show running-config or show interfaces or show protocols will provide the information.

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