L Lab - De esigning g and Im mplementing a S Subnette ed IPv4 A Address sing S Scheme e T Topology

A Addressing g Table Device R1 R

Interface

IP Add dress

S Subnet Mask

Default Gateway

G0/0

N/A

G0/1

N/A

Lo0

N/A

Lo1

N/A

S1 S

VLAN 1

PC-A P

NIC

PC-B P

NIC

N/A

N/A A

N/A

O Objectives Part 1: De esign a Netw work Subnettting Scheme 

Creatte a subnetting scheme tha at meets the required r num ber of subnetts and host ad ddresses.



Comp plete the diagram, showing g where the ho ost IP addressses will be ap pplied.

Part 2: Co onfigure the Devices 

Assign an IP addre ess, subnet mask, m and defa ault gateway to the PCs.



Config gure the route er Gigabit Eth hernet interfac ces with an IP P address and d subnet massk.



Creatte two loopback interfaces on the routerr, and configu ure each with an IP addresss and subnett mask.

Part 3: Te est and Troubleshoot the e Network 

Verify y and troubles shoot network k connectivity using ping.

B Backgroun nd / Scenarrio In this lab b, starting from m a single nettwork address s and networkk mask, you w will subnet the e network into o multiple subnets. The T subnet sc cheme should d be based on n the numberr of host comp puters require ed in each subnet, as well as other network considerations c s, like future network n host expansion.

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L Lab - Designing and Impllementing a Subnetted S IP Pv4 Address sing Scheme After you have created d a subnetting g scheme and d completed th he network diiagram by filling in the host and I addresses, you will configure the hos st PCs and ro outer interface es, including lloopback inte erfaces. interface IP The loopb back interface es are created d to simulate additional a LA ANs attached tto router R1. After the network n devic ces and host PCs have bee en configured d, you will use e the ping command to tesst for network connectivity. c This lab provides p minim mal assistanc ce with the acttual command ds necessaryy to configure the router. However, the requirred commands are provide ed in Appendix x A. Test you ur knowledge by trying to cconfigure the d devices without re eferring to the appendix. Note: The e routers used d with CCNA hands-on lab bs are Cisco 1 1941 Integrate ed Services R Routers (ISRss) with Cisco IOS S Release 15..2(4)M3 (univ versalk9 image). The switch hes used are e Cisco Catalyyst 2960s with h Cisco IOS Relea ase 15.0(2) (lanbasek9 ima age). Other ro outers, switch hes and Cisco o IOS version ns can be use ed. Depending on the mod del and Cisco IOS version, the comman nds available a and output prroduced migh ht vary from whatt is shown in the t labs. Refe er to the Routter Interface S Summary Tab ble at this end d of the lab fo or the correct intterface identiffiers. Note: Make sure that the routers an nd switches ha ave been era ased and have e no startup cconfigurationss. If you are unsurre, contact your instructor.

R Required Resources R 

1 Rou uter (Cisco 19 941 with Cisco o IOS Releas se 15.2(4)M3 universal ima age or compa arable)



1 Switch (Cisco 29 960 with Cisco o IOS Release 15.0(2) lanb basek9 image e or compara able)



2 PCs s (Windows 7, 7 Vista, or XP P with termina al emulation p program, such h as Tera Term)



Conso ole cables to configure the e Cisco IOS devices via the e console porrts



Ethernet cables as s shown in the e topology

e Gigabit Ethe ernet interface es on Cisco 1941 1 routers a are autosensiing. An Etherrnet straight-th hrough Note: The cable may y be used bettween the rou uter and PC-B B. If using ano other Cisco ro outer model, it may be neccessary to use an Ethernet crosso over cable.

P Part 1: Design D a Network N Subnetting Schem me S Step 1: Cre eate a subn netting sche eme that me eets the req quired numb ber of subn nets and req quired number of hos st addresse es. In this sce enario, you arre a network administrator a for a small su ubdivision witthin a larger ccompany. You u must create mu ultiple subnets s out of the 19 92.168.0.0/24 4 network add dress space tto meet the fo ollowing requirements: 

The first subnet is the employee e network. Yo ou need a min nimum of 25 h host IP addresses.



The second s subne et is the admin nistration netw work. You nee ed a minimum m of 10 IP add dresses.



The th hird and fourtth subnets are e reserved as s virtual netwo orks on virtua al router interffaces, loopbacck 0 and loopback 1. These virtual routerr interfaces simulate LANss attached to R R1.



You also a need two o additional un nused subnetts for future ne etwork expan nsion.

Note: Varriable length subnet s masks s will not be used. All of the e device subn net masks willl be the same e length. Answer th he following questions to help create a subnetting s sc heme that me eets the state ed network requireme ents: 1) How H many hos st addresses are needed in n the largest rrequired subn net? 2) What W is the minimum number of subnets s required?

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Lab - Designing and Implementing a Subnetted IPv4 Addressing Scheme 3) The network that you are tasked to subnet is 192.168.0.0/24. What is the /24 subnet mask in binary?

4) The subnet mask is made up of two portions, the network portion, and the host portion. This is represented in the binary by the ones and the zeros in the subnet mask. In the network mask, what do the ones represent? In the network mask, what do the zeros represent? 5) To subnet a network, bits from the host portion of the original network mask are changed into subnet bits. The number of subnet bits defines the number of subnets. Given each of the possible subnet masks depicted in the following binary format, how many subnets and how many hosts are created in each example? Hint: Remember that the number of host bits (to the power of 2) defines the number of hosts per subnet (minus 2), and the number of subnet bits (to the power of two) defines the number of subnets. The subnet bits (depicted in bold type face) are the bits that have been borrowed beyond the original network mask of /24. The /24 is the slash prefix notation and corresponds to a dotted decimal mask of 255.255.255.0.

(/25) 11111111.11111111.11111111.10000000 Dotted decimal subnet mask equivalent: Number of subnets?

Number of hosts?

(/26) 11111111.11111111.11111111.11000000 Dotted decimal subnet mask equivalent: Number of subnets?

Number of hosts?

(/27) 11111111.11111111.11111111.11100000 Dotted decimal subnet mask equivalent: Number of subnets?

Number of hosts?

(/28) 11111111.11111111.11111111.11110000 Dotted decimal subnet mask equivalent: Number of subnets?

Number of hosts?

(/29) 11111111.11111111.11111111.11111000 Dotted decimal subnet mask equivalent: Number of subnets?

Number of hosts?

(/30) 11111111.11111111.11111111.11111100 Dotted decimal subnet mask equivalent: Number of subnets?

Number of hosts?

6) Considering your answers, which subnet masks meet the required number of minimum host addresses?

7) Considering your answers, which subnet masks meets the minimum number of subnets required?

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L Lab - Designing and Impllementing a Subnetted S IP Pv4 Address sing Scheme 8) Considering C yo our answers, which subnett mask meetss both the required minimum number of hosts an nd the minimu um number of o subnets req quired?

W you hav ve determined d which subne et mask meetts all of the sta ated network requirementss, you will 9) When de erive each of the subnets starting s from the original n network addre ess. List the subnets from ffirst to la ast below. Rem member that the first subn net is 192.168 8.0.0 with the newly acquire ed subnet ma ask. Subnet Address A

/ Prefix Su ubnet Mask ((dotted decim mal) / / / / / / / / / /

S Step 2: Co omplete the diagram sh howing whe ere the hostt IP address ses will be a applied. On the folllowing lines provided, p fill in n the IP addre esses and su ubnets maskss in slash preffix notation. O On the router, use the first usa able address in each subne et for each off the interface es, Gigabit Eth hernet 0/0, Gigabit Ethernet 0/1, 0 loopback k 0, and loopb back 1. Fill in an a IP addresss for both PC C-A and PC-B. Also enter th his informatio on into the Addressing Tab ble on Page 1.

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L Lab - Designing and Impllementing a Subnetted S IP Pv4 Address sing Scheme

P Part 2: Configure C e the Devices In Part 2, set up the ne etwork topolog gy and configure basic setttings on the P PCs and route er, such as th he router Gigabit Etthernet interfa ace IP addres sses, and the PC’s IP addrresses, subne et masks, and d default gate eways. Refer to th he Addressing Table for de evice names and address information. Note: App pendix A prov vides configurration details for the steps in Part 2. You u should attem mpt to comple ete Part 2 prior to re eviewing Appe endix A.

S Step 1: Co onfigure the e router. a. Enter into privilege ed EXEC mod de and then global config m mode. b. Assign the R1 as the hostname for the router. c.

Config gure both the e G0/0 and G0 0/1 interfaces s with IP addre esses and su ubnet masks, and then ena able them.

d. Loopb back interface es are created d to simulate additional LA ANs on R1 rou uter. Configurre the loopbacck interfa aces with IP addresses a and subnet mas sks. After theyy are created d, loopback intterfaces are e enabled, by default. (To crea ate the loopback addresse es, enter the ccommand inte erface loopb back 0 at the global config g mode) Note: You can create additional loopbacks fo or testing with h different add dressing sche emes, if desirred. e. Save the running configuration c to t the startup p configuration n file.

S Step 2: Co onfigure the e PC interfac ces. a. Config gure the IP ad ddress, subne et mask, and default gatew way settings o on PC-A. b. Config gure the IP ad ddress, subne et mask, and default gatew way settings o on PC-B.

P Part 3: Test T and Troubles T hoot the Network In Part 3, you will use the t ping command to test network conn nectivity. C-A, open a ccommand pro a. Test to t see if PC-A A can communicate with its s default gate eway. From PC ompt and ping the t IP address s of the route er Gigabit Ethe ernet 0/1 inte erface. Do you u get a reply? ? b. Test to t see if PC-B B can communicate with its s default gate eway. From PC C-B, open a ccommand pro ompt and ping the t IP address s of the route er Gigabit Ethe ernet 0/0 inte erface. Do you u get a reply? ? c.

Test to t see if PC-A A can communicate with PC C-B. From PC C-A, open a ccommand pro ompt and ping g the IP addre ess of PC-B. Do D you get a reply?

d. If you answered “no” to any of th he preceding questions, th hen you should go back an nd check all o of your IP addre ess and subne et mask config gurations, and ensure thatt the default g gateways havve been correctly config gured on PC-A A and PC-B. e. If you verify that all of the setting gs are correct, and you ca an still not ping g successfullyy, then there are a few additional factors that can block k ICMP pings.. On PC-A an nd PC-B within n Windows, m make sure tha at the Windo ows Firewall is i turned off fo or the Work, Home, and P Public networkks. f.

Experriment by purposely misconfiguring the gateway add ress on PC-A A to 10.0.0.1. What happen ns when you trry and ping fro om PC-B to PC-A? P Do you u receive a re eply?

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Lab - Designing and Implementing a Subnetted IPv4 Addressing Scheme

Reflection 1. Subnetting one larger network into multiple smaller subnetworks allows for greater flexibility and security in network design. However, what do you think some of the drawbacks are when the subnets are limited to being the same size?

2. Why do you think the gateway/router IP address is usually the first usable IP address in the network?

Router Interface Summary Table Router Interface Summary Router Model

Ethernet Interface #1

Ethernet Interface #2

Serial Interface #1

Serial Interface #2

1800

Fast Ethernet 0/0 (F0/0)

Fast Ethernet 0/1 (F0/1)

Serial 0/0/0 (S0/0/0)

Serial 0/0/1 (S0/0/1)

1900

Gigabit Ethernet 0/0 (G0/0)

Gigabit Ethernet 0/1 (G0/1)

Serial 0/0/0 (S0/0/0)

Serial 0/0/1 (S0/0/1)

2801

Fast Ethernet 0/0 (F0/0)

Fast Ethernet 0/1 (F0/1)

Serial 0/1/0 (S0/1/0)

Serial 0/1/1 (S0/1/1)

2811

Fast Ethernet 0/0 (F0/0)

Fast Ethernet 0/1 (F0/1)

Serial 0/0/0 (S0/0/0)

Serial 0/0/1 (S0/0/1)

2900

Gigabit Ethernet 0/0 (G0/0)

Gigabit Ethernet 0/1 (G0/1)

Serial 0/0/0 (S0/0/0)

Serial 0/0/1 (S0/0/1)

Note: To find out how the router is configured, look at the interfaces to identify the type of router and how many interfaces the router has. There is no way to effectively list all the combinations of configurations for each router class. This table includes identifiers for the possible combinations of Ethernet and Serial interfaces in the device. The table does not include any other type of interface, even though a specific router may contain one. An example of this might be an ISDN BRI interface. The string in parenthesis is the legal abbreviation that can be used in Cisco IOS commands to represent the interface.

Appendix A: Configuration Details for Steps in Part 2 Step 1: Configure the router. a. Console into the router and enable privileged EXEC mode. Router> enable Router#

b. Enter into configuration mode. Router# conf t Enter configuration commands, one per line.

End with CNTL/Z.

Router(config)# c.

Assign a device name to the router.

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L Lab - Designing and Impllementing a Subnetted S IP Pv4 Address sing Scheme Route er(config)# hostname e R1 R1(co onfig)#

d. Config gure both the e G0/0 and G0 0/1 interfaces s with IP addre esses and su ubnet masks, and enable th hem. R1(co onfig)# in nterface g0 0/0 R1(co onfig-if)# # ip addres ss > R1(co onfig-if)# # no shutdo own R1(co onfig-if)# # interface e g0/1 R1(co onfig-if)# # ip addres ss > R1(co onfig-if)# # no shutdo own e. Loopb back interface es are created d to simulate additional LA ANs off of routter R1. Config gure the loopback interfa aces with IP addresses a and subnet mas sks. When the ey are created, loopback in nterfaces are e enabled, by default. onfig)# in nterface lo oopback 0 R1(co R1(co onfig-if)# # ip addres ss > R1(co onfig-if)# # interface e loopback k 1 R1(co onfig-if)# # ip addres ss > R1(co onfig-if)# # end f.

Save the running configuration c to t the startup p configuration n file. c runni ing-config startup-c config R1# copy

S Step 2: Co onfigure the e PC interfac ces. a. Config gure the IP ad ddress, subne et mask, and default gatew way settings o on PC-A.

b. Config gure the IP ad ddress, subne et mask, and default gatew way settings o on PC-B.

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