4. Practicals

Hands-on labs in Cisco Packet Tracer and Linux. Work through them in order: each one builds skills you need for Assignment 2.

Before you start

  1. Getting around Packet Tracer
  2. Build and test a small LAN
  3. Wired and wireless together
  4. DHCP, DNS, web and email servers
  5. Secure a switch with IOS
  6. Connect two LANs with a router
  7. Two sites and a static route
  8. VLANs on a switch
  9. Linux users, groups and permissions
  10. Troubleshooting challenge

Lab 1: Getting around Packet Tracer

20 minLesson A1a
  1. Open Packet Tracer. Find the device boxes at the bottom left: Network Devices (routers, switches, wireless) and End Devices (PCs, laptops, servers).
  2. Drag in a PC and click it. Look at the Physical, Config and Desktop tabs. The Desktop tab has IP Configuration, Command Prompt and Web Browser.
  3. Find the Connections (lightning bolt) icon. The automatic connection picks the right cable for you; copper straight-through is the normal PC-to-switch cable.
  4. Find the Realtime / Simulation switch at the bottom right. Simulation mode lets you watch packets move one step at a time.
  5. Switch between the Logical and Physical workspace views at the top left.
Evidence: none needed; this is practice.

Lab 2: Build and test a small LAN

30 minLessons A1b, A2a
  1. Add a 2960 switch and three PCs. Connect each PC's FastEthernet0 to a switch port.
  2. Wait for the link lights to turn green (orange means the switch port is still starting up).
  3. Give the PCs static addresses in Desktop → IP Configuration: 192.168.1.10, .11 and .12, all with mask 255.255.255.0.
  4. On PC0 open Command Prompt and type ping 192.168.1.11.
  5. Now change PC2's mask to 255.255.0.0 and its address to 192.168.2.12. Ping it again and explain why it fails.
Check it works: four replies from each ping in the same network.
Evidence: screenshot of the topology and of one successful ping.

Lab 3: Wired and wireless together

30 minLessons A1a, A2a
  1. Start from Lab 2. Add an AccessPoint-PT and connect it to the switch.
  2. Click the access point: Config → Port 1. Set the SSID to OFFICE-STAFF, choose WPA2-PSK and a passphrase of at least 12 characters.
  3. Add a laptop. Power it off (button on the Physical tab), drag out the Ethernet module, drag in WPC300N, then power on.
  4. On the laptop: Config → Wireless0. Enter the same SSID, WPA2-PSK and passphrase.
  5. Give the laptop 192.168.1.20/24 and ping a wired PC.
Check it works: a dotted wireless link appears and the ping succeeds. Try a wrong passphrase to prove the security works.
Evidence: the AP security settings and a successful ping from the laptop.

Lab 4: DHCP, DNS, web and email servers

45 minLesson A4
  1. Add a Server-PT to your LAN and give it the static address 192.168.1.2/24.
  2. DHCP: Services → DHCP. Default gateway 192.168.1.1, DNS server 192.168.1.2, start address 192.168.1.100, maximum users 50. Save, and switch the service On.
  3. DNS: Services → DNS. Add an A record: name intranet.local, address 192.168.1.2. Add mail.local the same way. Switch DNS On.
  4. Web: Services → HTTP. Edit index.html so it shows your own intranet heading.
  5. Email: Services → EMAIL. Domain name mail.local; add two users with passwords. On two PCs set up Desktop → Email with those accounts, incoming and outgoing server mail.local, and send a message between them.
  6. Set every PC to DHCP in IP Configuration.
Check it works: PCs get addresses from .100 upwards; intranet.local opens in the browser; the email arrives.
Evidence: each service's settings; ipconfig /all on a PC; the web page; the received email.

Lab 5: Secure a switch with Cisco IOS

30 minLesson C1

Click the switch, open the CLI tab and press Enter.

enable
configure terminal
hostname LAB-SW01
enable secret Lab-Enable-2026
line console 0
 password Lab-Console-26
 login
 exit
line vty 0 15
 password Lab-Remote-26
 login
 exit
service password-encryption
banner motd # Authorised users only #
interface vlan 1
 ip address 192.168.1.250 255.255.255.0
 no shutdown
 exit
ip default-gateway 192.168.1.1
end
copy running-config startup-config
Check it works: type exit and press Enter: the banner and a password prompt appear. show running-config shows encrypted (type 7 or secret) passwords.
Evidence: show running-config with passwords encrypted; the login prompt.

Lab 6: Connect two LANs with a router

45 minLessons A2a, B1b, C1
  1. Build two LANs, each with a switch and two PCs. Add a 2911 router and connect G0/0 to switch 1 and G0/1 to switch 2.
  2. Configure the router:
enable
configure terminal
hostname LAB-R1
interface g0/0
 ip address 192.168.10.1 255.255.255.0
 no shutdown
interface g0/1
 ip address 192.168.20.1 255.255.255.0
 no shutdown
end
show ip interface brief
  1. LAN 1 PCs: 192.168.10.10 and .11, gateway 192.168.10.1. LAN 2 PCs: 192.168.20.10 and .11, gateway 192.168.20.1.
  2. Ping from a LAN 1 PC to a LAN 2 PC. Then run tracert to see the router in the path.
  3. Remove one PC's default gateway and ping again. Explain the result.
Check it works: show ip interface brief shows both interfaces up/up, and cross-LAN pings succeed.
Evidence: show ip interface brief, a cross-network ping and the tracert output.

Lab 7: Two sites and a static route

45 minLessons B1b, C1

This models a head office and a branch office, like Assignment 2.

  1. Add a second router (branch) with its own switch and PCs on 192.168.30.0/24.
  2. Connect the two routers with a cable between spare interfaces, and give that link its own small network, e.g. 10.0.0.1/30 on head office and 10.0.0.2/30 on the branch.
  3. Tell each router how to reach the other site's LAN:
! on the head-office router
ip route 192.168.30.0 255.255.255.0 10.0.0.2
! on the branch router
ip route 192.168.10.0 255.255.255.0 10.0.0.1
  1. Ping from a branch PC to a head-office PC. Check show ip route on both routers: static routes show as S.
  2. Stretch: remove the static routes and use router rip (version 2) with network statements instead. Compare the routing tables.
Evidence: both routing tables and a ping between sites.

Lab 8: VLANs on a switch

40 minLesson B1b
enable
configure terminal
vlan 10
 name STAFF
vlan 20
 name GUEST
interface range fa0/1 - 8
 switchport mode access
 switchport access vlan 10
interface range fa0/9 - 12
 switchport mode access
 switchport access vlan 20
interface range fa0/13 - 24
 shutdown
end
show vlan brief
  1. Put two PCs on ports 1–2 (VLAN 10) and two on ports 9–10 (VLAN 20), all in the same IP network.
  2. Ping within a VLAN (works) and across VLANs (fails). Explain why, and what would be needed to allow it.
Evidence: show vlan brief, one working and one failed ping with your explanation.

Lab 9: Linux users, groups and permissions

45 minLesson B3

Use the Linux terminal your teacher provides. Linux is case sensitive. This lab uses example names: use the names and groups from your own brief in your assignment.

sudo groupadd sales
sudo groupadd support
sudo useradd -m -G sales ria
sudo useradd -m -G support ben
sudo passwd ria
sudo mkdir -p /srv/share/sales /srv/share/support
sudo chown $USER:sales /srv/share/sales
sudo chown $USER:support /srv/share/support
sudo chmod 770 /srv/share/sales
sudo chmod 755 /srv/share/support
ls -l /srv/share
id ria
  1. Read the ls -l output: which user owns each folder, which group, and what can others do?
  2. Switch user (su - ria) and try to open each folder with cd and ls. Record what is allowed and what is denied.
  3. Work out the chmod number that would let others read but not change a folder, and test it.
Evidence: the ls -l output and your access tests (allowed and denied).

Lab 10: Troubleshooting challenge

40 minLesson C2

Your teacher or a partner breaks a working network from Lab 6 or 7 in secret, using some of these faults. Find and fix each one using the method in lesson C2, and document it.

SymptomTest I ranCause I foundFixRe-test result
 
 
Evidence: this completed table: excellent practice for the C.P6 test evidence.