Cisco Packet Tracer cheat sheet

All Essential Commands for Routers, Switches, and Network Basics

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Basic Device Navigation

Command	Description
enable	Enter privileged EXEC mode (admin access).
configure terminal	Enter global configuration mode.
exit	Go back one level.
end	Exit configuration mode completely.

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Device Setup

Set Hostname

Router> enable  
Router# configure terminal  
Router(config)# hostname R1  # Rename router to "R1"  

Set Banner Message

R1(config)# banner motd #Unauthorized Access Prohibited#  

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Interface Configuration

Assign IP Address to Interface

R1(config)# interface gigabitethernet0/0  
R1(config-if)# ip address 192.168.1.1 255.255.255.0  
R1(config-if)# no shutdown  # Turn on the interface  

Set Interface Description

R1(config-if)# description "Connected to Office LAN"  

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Password Security

Console Password

R1(config)# line console 0  
R1(config-line)# password cisco  
R1(config-line)# login  

Enable Secret Password

R1(config)# enable secret class123  # Encrypted password  

VTY (Remote Access) Password

R1(config)# line vty 0 4  
R1(config-line)# password cisco  
R1(config-line)# login  
R1(config-line)# transport input ssh  # Restrict to SSH  

Encrypt Passwords

R1(config)# service password-encryption  

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Routing Basics

Static Route

R1(config)# ip route 192.168.2.0 255.255.255.0 10.0.0.2  
# Route traffic for 192.168.2.0 to next-hop 10.0.0.2  

RIP Configuration

R1(config)# router rip  
R1(config-router)# version 2  
R1(config-router)# network 192.168.1.0  

OSPF Configuration

R1(config)# router ospf 1  
R1(config-router)# network 192.168.1.0 0.0.0.255 area 0  

EIGRP Configuration

R1(config)# router eigrp 100  
R1(config-router)# network 192.168.1.0  

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Switch Configuration

VLAN Setup

Switch(config)# vlan 10  
Switch(config-vlan)# name Sales  

Assign Port to VLAN

Switch(config)# interface fastethernet0/1  
Switch(config-if)# switchport mode access  
Switch(config-if)# switchport access vlan 10  

Trunk Port Configuration

Switch(config-if)# switchport mode trunk  

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SSH Configuration

R1(config)# ip domain-name example.com  
R1(config)# crypto key generate rsa  # Use 1024-bit key  
R1(config)# username admin secret AdminPass  
R1(config)# line vty 0 4  
R1(config-line)# login local  # Use local username/password  
R1(config-line)# transport input ssh  

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Troubleshooting Commands

Command	Description
show ip interface brief	Check interface status & IPs
show running-config	View current configuration
ping 192.168.1.1	Test connectivity
traceroute 8.8.8.8	Trace the path to a destination
show cdp neighbors	Discover connected devices

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Save & Backup

R1# copy running-config startup-config  # Save config  
R1# copy running-config tftp://192.168.1.5/backup.cfg  # Backup to TFTP  

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Common Mistakes to Avoid

❌ Forgetting no shutdown on interfaces. ❌ Using weak passwords like "cisco" or "admin". ❌ Missing subnet masks in network statements for routing protocols.

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Step-by-Step Example: Basic Network Setup

1. Connect Devices: Use copper straight-through cables for switches/hosts.

2. Assign IPs:

   PC> ipconfig 192.168.1.2 255.255.255.0 192.168.1.1  

3. Verify Connectivity:

   PC> ping 192.168.1.1  

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Pro Tip

Use Packet Tracer’s Simulation Mode to watch packets travel through your network!

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