Lesson 1 of 5
CLI Modes and Navigation
Lab Objectives
- Learn and practice navigating the IOS Command-Line Interface (CLI) modes: User EXEC, Privileged EXEC, Global Configuration, and Interface Configuration.
- Configure basic interface IP addressing on R1 from the provided base topology and verify configuration using show commands.
- Understand WHY each mode exists and WHEN to use it in a production network.
Lab Tasks (Try It Yourself First!)
Complete these tasks WITHOUT looking at the solution below. Use
?andshowcommands to figure it out.
Task 1: Enter Privileged EXEC and Inspect Interfaces
On R1, move from User EXEC into Privileged EXEC and run a command to list all interfaces and their IP addresses and statuses. Do not change configuration yet.
Parameters:
- Device: R1 (Gateway)
Task 2: Enter Global Configuration and Set Hostname + Interface IPs
Change the device hostname to a descriptive name and configure the three GigabitEthernet interfaces on R1 with the IP addresses shown in the topology. Bring the interfaces up.
Parameters:
- Hostname: R1
- Gi0/0: 10.10.10.1/24
- Gi0/1: 10.10.20.1/24
- Gi0/2: 10.10.30.1/24
- Ensure interfaces are not shutdown.
Task 3: Configure a Default Route to the Internet and Verify
While in Global Configuration, add a default static route pointing to the Internet device (203.0.113.1). Then verify the routing and interface configuration.
Parameters:
- Default route next-hop: 203.0.113.1
Think About It: Why do you need different CLI modes (User EXEC vs Privileged EXEC vs Global Config)? Which mode protects the device from accidental destructive changes, and how does that matter in production?
Lab Solution
Task 1 Solution: Enter Privileged EXEC and Inspect Interfaces
What we are doing: We will move from the limited User EXEC prompt into Privileged EXEC (which allows configuration viewing and access to higher-level commands), then list interface IPs and statuses to see the starting state.
R1> enable
R1# show ip interface brief
What just happened:
enable— moves you from User EXEC (limited commands) to Privileged EXEC (full show and debugging commands). This mode is required before entering configuration modes. In a production router, this prevents accidental changes from casual users.show ip interface brief— displays a concise table of interfaces, IP addresses, and up/down status. This is the fastest way to confirm interface addressing and line/protocol state.
Verify:
R1# show ip interface brief
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/0 10.10.10.1 YES manual up up
GigabitEthernet0/1 10.10.20.1 YES manual up up
GigabitEthernet0/2 10.10.30.1 YES manual up up
Loopback0 unassigned YES unset administratively down down
Tip: If
show ip interface briefshowsunassignedfor an interface you expected to configure, you are probably still in User EXEC and forgot toenable, or the interface was not configured yet.
Task 2 Solution: Enter Global Configuration and Set Hostname + Interface IPs
What we are doing: Enter Global Configuration mode to make persistent configuration changes, set the device hostname, and assign IP addresses to the three GigabitEthernet interfaces and bring them up.
R1# configure terminal
R1(config)# hostname R1
R1(config)# interface GigabitEthernet0/0
R1(config-if)# ip address 10.10.10.1 255.255.255.0
R1(config-if)# no shutdown
R1(config-if)# exit
R1(config)# interface GigabitEthernet0/1
R1(config-if)# ip address 10.10.20.1 255.255.255.0
R1(config-if)# no shutdown
R1(config-if)# exit
R1(config)# interface GigabitEthernet0/2
R1(config-if)# ip address 10.10.30.1 255.255.255.0
R1(config-if)# no shutdown
R1(config-if)# end
R1#
What just happened:
configure terminal— enters Global Configuration where you can modify device configuration; think of it as unlocking the toolbox to make changes.hostname R1— sets the device prompt to reflect the hostname; this is important in multi-device environments so you always know which device you are on.interface GigabitEthernet0/0(and others) — enters Interface Configuration mode for that interface; the prompt changes to indicate scope.ip address <ip> <mask>— assigns the IPv4 address to the interface. This is how the interface participates in the network.no shutdown— administratively enables the interface. By default some interfaces can be shut down;no shutdownactivates the interface so it can pass traffic.exit/end— leaves the current configuration mode back to Global or Privileged mode.
Verify:
R1# show running-config | include hostname|interface GigabitEthernet0/0|interface GigabitEthernet0/1|interface GigabitEthernet0/2|ip address
hostname R1
interface GigabitEthernet0/0
ip address 10.10.10.1 255.255.255.0
no shutdown
interface GigabitEthernet0/1
ip address 10.10.20.1 255.255.255.0
no shutdown
interface GigabitEthernet0/2
ip address 10.10.30.1 255.255.255.0
no shutdown
R1# show ip interface brief
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/0 10.10.10.1 YES manual up up
GigabitEthernet0/1 10.10.20.1 YES manual up up
GigabitEthernet0/2 10.10.30.1 YES manual up up
Loopback0 unassigned YES unset administratively down down
<div class="topology-diagram">
<img src="data:image/svg+xml;base64,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" alt="Network Topology Diagram" style="max-width:100%;height:auto;background:#fff;padding:16px;border:1px solid #e5e7eb;border-radius:8px;" />
</div>
cisco
R1# configure terminal
R1(config)# ip route 0.0.0.0 0.0.0.0 203.0.113.1
R1(config)# end
R1# show ip route
What just happened:
ip route 0.0.0.0 0.0.0.0 203.0.113.1— creates a default route (match-all) pointing to the Internet next-hop. In production, this ensures any traffic with no more specific route is forwarded toward the Internet provider.- Adding a default route is a common practice at edge routers; it keeps routing tables small and practical for general Internet traffic.
Verify:
R1# show ip route
Codes: C - connected, S - static, R - RIP, B - BGP, O - OSPF, I - IS-IS
S* 0.0.0.0/0 [1/0] via 203.0.113.1
C 10.10.10.0/24 is directly connected, GigabitEthernet0/0
C 10.10.20.0/24 is directly connected, GigabitEthernet0/1
C 10.10.30.0/24 is directly connected, GigabitEthernet0/2
R1# show ip interface brief
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/0 10.10.10.1 YES manual up up
GigabitEthernet0/1 10.10.20.1 YES manual up up
GigabitEthernet0/2 10.10.30.1 YES manual up up
<div class="topology-diagram">
<img src="data:image/svg+xml;base64,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" alt="Network Topology Diagram" style="max-width:100%;height:auto;background:#fff;padding:16px;border:1px solid #e5e7eb;border-radius:8px;" />
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cisco
R1# show running-config interface GigabitEthernet0/1
interface GigabitEthernet0/1
ip address 10.10.20.1 255.255.255.0
shutdown
Explanation:
- The interface was configured with
shutdown, which places it in the administratively down state. - Fix by removing the shutdown and verifying:
R1# configure terminal
R1(config)# interface GigabitEthernet0/1
R1(config-if)# no shutdown
R1(config-if)# end
R1# show ip interface brief | include GigabitEthernet0/1
GigabitEthernet0/1 10.10.20.1 YES manual up up
Verification Checklist
- Entered Privileged EXEC (
enable) successfully. - Set hostname to R1 in Global Configuration mode.
- Configured IP addresses and issued
no shutdownon Gi0/0, Gi0/1, Gi0/2. - Added default static route pointing to 203.0.113.1.
- Verified with
show ip interface brief,show running-config, andshow ip route.
Common Mistakes
| Symptom | Cause | Fix |
|---|---|---|
| Interface shows "administratively down" | shutdown present under interface config | Enter interface config and no shutdown |
| Wrong IP or mask on interface | Typo or incorrect mask length | Re-enter ip address <ip> <mask> with correct values |
| Default route absent | Did not save or omitted ip route command | Reconfigure with ip route 0.0.0.0 0.0.0.0 203.0.113.1 |
| Still in User EXEC | Forgot to issue enable | Run enable to access Privileged EXEC |
Challenge Task
Configure R2 so its Gi0/0 is 10.10.10.2/24 and Gi0/1 is 10.10.40.1/24 (link to S1). Do not follow step-by-step instructions — use your knowledge of modes to enter Global Config and Interface Config and verify with show ip interface brief. (All addresses are in the base topology.)
Important: Practice using
?to discover subcommands andexitto move up a mode level. In production, disciplined movement between modes and frequent use ofshowcommands reduce mistakes and speed troubleshooting.