Cisco CCNA Preparation · lesson 7 of 36 · 25 min
Initial Device Setup
Every Cisco device needs a baseline configuration before it can be managed securely. The CCNA exam tests your ability to configure hostnames, passwords, banners, and interface IP addresses from the CLI.
Essential Configuration Commands
enable password vs enable secret
Always use enable secret — it stores the password as an MD5 hash. enable password stores it in plaintext (visible in show running-config). If both are set, enable secret takes precedence.
Interface Configuration Walkthrough
To bring up a router interface with an IP address:
- Router# configure terminal
- Router(config)# interface GigabitEthernet0/0
- Router(config-if)# ip address 192.168.1.1 255.255.255.0
- Router(config-if)# description LAN Interface
- Router(config-if)# no shutdown
- Router(config-if)# end
- Router# copy running-config startup-config
no shutdown is critical — Cisco router interfaces are administratively down by default. Switch ports are up by default.
Verifying Configuration
Flashcard Drill
enable secret Sets the Privileged EXEC password as an MD5 hash — always prefer over enable password. service password-encryption Encrypts all plaintext passwords in the running config. no shutdown Enables a router interface — required because router interfaces are admin-down by default. banner motd Sets a Message of the Day login banner — displayed before authentication. show ip interface brief Quick summary of all interfaces: IP address, status (up/down), and protocol. line vty 0 4 Configures VTY lines 0–4 for remote access (SSH/Telnet). hostname Sets the device name — appears in the CLI prompt. copy running-config startup-config Saves active config to NVRAM — survives reboot. show version Displays IOS version, uptime, hardware model, and memory. interface GigabitEthernet0/0 Enters interface configuration mode for GigabitEthernet 0/0.
Knowledge Check
Basic Configuration — 10 Questions
Which command sets an encrypted Privileged EXEC password?
- enable password Cisco
- enable secret Cisco
- password enable Cisco
- service password-encryption
Answer: enable secret Cisco
enable secret stores the password as an MD5 hash. enable password stores it in plaintext.
Cisco router interfaces are enabled (up) by default.
- True
- False
Answer: False
Router interfaces are administratively down by default — you must issue no shutdown to enable them.
Which command provides a quick summary of all interface IPs and statuses?
- show interfaces
- show running-config
- show ip interface brief
- show version
Answer: show ip interface brief
show ip interface brief shows interface name, IP, and up/down status in a compact table.
The command _____ encrypts all plaintext passwords in the running configuration.
Answer: service password-encryption
service password-encryption applies weak Type 7 encryption to all plaintext passwords.
Where is the running-config stored?
- NVRAM
- Flash
- RAM
- ROM
Answer: RAM
The running-config is in RAM — volatile, lost on reboot unless saved.
Which command sets a login banner displayed before authentication?
- banner login
- banner motd
- motd banner
- login banner
Answer: banner motd
banner motd (Message of the Day) is displayed to users before they authenticate.
To configure SSH access on VTY lines, which line range is typically used?
- line console 0
- line vty 0 4
- line aux 0
- line tty 0
Answer: line vty 0 4
line vty 0 4 configures the 5 virtual terminal lines used for SSH and Telnet.
If both enable password and enable secret are configured, enable password takes precedence.
- True
- False
Answer: False
enable secret always takes precedence over enable password when both are configured.
Which command shows the IOS version and device uptime?
- show interfaces
- show ip interface brief
- show running-config
- show version
Answer: show version
show version displays IOS version, uptime, hardware model, memory, and license info.
To enable a router interface, you must issue the _____ command in interface configuration mode.
Answer: no shutdown
no shutdown removes the administrative shutdown and brings the interface up.
Previous lesson: IPv6 addressing, prefix notation, and address types (unicast, anycast, multicast, EUI-64)
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