Cisco CLI Simulator

Interactive Cisco CLI simulator for practicing networking commands and device configuration in an isolated, safe environment.

Table of Contents

1. Installation & Setup
2. Getting Started
3. Navigation Basics
4. Device Management
5. Interfaces Configuration
6. Routing
7. Switching & VLANs
8. Security
9. Monitoring & Diagnostics
10. QoS & Services
11. Docker Usage
12. Troubleshooting

Installation & Setup

Global Installation (via npm)

Install the package globally from npm registry:

npm install @cisco-cli/simulator

Then run it using:

npx cisco-cli

You should see:

  Cisco CLI Simulator
  ─────────────────────────────

  Select category:

Local Installation

Prerequisites:

• Node.js 14.0 or higher
• npm 6.0 or higher

Steps:

1. Clone or download the repository

   git clone https://github.com/girish-kor/cisco-cli.git
   cd cisco-cli

2. Install dependencies

   npm install

3. Start the simulator

   npm start

You should see:

  Cisco CLI Simulator
  ─────────────────────────────

  Select category:

Update Installation

To update to the latest version:

git pull origin main
npm install
npm start

Getting Started

First Run

1. Execute npm start
2. You'll see the main menu with 7 categories
3. Use arrow keys to navigate
4. Press Enter to select an option
5. Type Exit or select Exit to quit

Available Categories

Each category contains multiple operations:

• Device Management — View version, config, save settings
• Interfaces — Configure IP addresses, toggle ports, descriptions
• Routing — Static routes, OSPF, BGP configuration
• Switching — VLANs, trunk/access modes, STP
• Security — ACLs, SSH, user management
• Monitoring — Ping, traceroute, logs
• QoS / Services — Quality of Service policies, DHCP pools

Navigation Basics

Menu Navigation

• Arrow Keys — Move up/down between options
• Enter — Select highlighted option
• Number Keys — Quickly select by number (when applicable)
• Q / Escape — Exit current prompt (varies by context)

Input Types

Text Input:

? Enter hostname: router-01

Just type and press Enter.

Yes/No Confirmation:

? Reload device? (Y/n)

Type y or Y for yes, n or N for no, or just press Enter for default.

List Selection:

? Select interface: (Use arrow keys)
  ❯ Gi0/0
    Gi0/1
    Gi1/0

Use arrow keys to highlight, then press Enter.

Number Input:

? VLAN ID (1-4094): 10

Type the number and press Enter.

Device Management

Manage basic device properties and configurations.

View Device Version

Path: Device Management → Show Version

What it displays:

• IOS version
• Hostname
• Uptime
• Processor details
• Memory info (NVRAM, Flash)

Use case: Verify device specifications and current uptime.

View Running Configuration

Path: Device Management → Show Running Config

What it displays:

• Current hostname
• All configured interfaces with IP addresses and state
• All configured static routes
• ACLs, OSPF, BGP settings (if configured)

Use case: Review all active configurations currently in effect.

View Startup Configuration

Path: Device Management → Show Startup Config

What it displays:

• Exact copy of the last saved configuration
• Shows what will be loaded on next device reload

Use case: Verify saved settings match your current running config.

Save Configuration

Path: Device Management → Save Configuration

What it does:

• Writes current running config to NVRAM (non-volatile memory)
• Saves configuration so it persists after reload

Steps:

1. Select "Save Configuration"
2. Wait for "Writing to NVRAM..." to complete
3. See success message: "Configuration saved to NVRAM."

Important: Always save before exit if you want to keep changes!

Reload Device

Path: Device Management → Reload

What it does:

• Simulates device restart
• Reloads from startup config
• Clears unsaved changes

Steps:

1. Select "Reload"
2. Confirm: "Reload device? Unsaved changes will be lost."
3. Type y to confirm or n to cancel
4. Device restarts (simulated)

Warning: Unsaved running config is lost. Save first if you need changes!

Interfaces Configuration

Configure network interface IP addresses, descriptions, and line states.

Configure Interface IP

Path: Interfaces → Configure Interface

Steps:

1. Enter interface name (examples: Gi0/0, Fa0/1, Eth0)
2. Enter IP address (example: 192.168.1.1)
3. Enter subnet mask (example: 255.255.255.0)
4. Interface state automatically changes to up

Result: Interface is active and assigned to the network.

Example:

? Interface to configure: Gi0/0
? IP address: 10.1.1.1
? Subnet mask: 255.255.255.0
✓ Gi0/0 → 10.1.1.1/255.255.255.0 (up)

Show Interface Status

Path: Interfaces → Show Interface Status

What it displays:

• Interface name
• Current state (up/down)
• IP address and subnet mask (if configured)
• Description (if set)

Example output:

  Gi0/0                          up         10.1.1.1/255.255.255.0
    desc: Link to Core
  Gi0/1                          down       unassigned
  Fa1/0                          up         172.16.1.1/255.255.255.0

Toggle Interface State

Path: Interfaces → Toggle Interface State

What it does:

• Enables (shutdown/no shutdown) or disables interface
• Toggles between up and down

Steps:

1. Select interface name
2. State automatically switches

Typical use:

• Disable problematic interface: set to down
• Re-enable after troubleshooting: set to up

Set Interface Description

Path: Interfaces → Set Interface Description

What it does:

• Adds or updates descriptive text on interface
• Helps identify interface purpose
• Shown in interface status listings

Steps:

1. Select interface
2. Enter description (example: Link to core router or Connect to switch-1)

Example:

? Interface: Gi0/0
? Description: Primary uplink to ISP
✓ Description set on Gi0/0

Assign Interface to VLAN

Path: Interfaces → Assign to VLAN

What it does:

• Assigns Layer 2 interface to specific VLAN
• Only works on access mode interfaces

Steps:

1. Select interface
2. Enter VLAN ID (1–4094, typically 1–100 for practice)

Example:

? Interface: Fa1/0
? VLAN ID: 20
✓ VLAN 20 assigned to Fa1/0

Routing

Configure static routes, dynamic routing protocols (OSPF, BGP).

Add Static Route

Path: Routing → Add Static Route

What it does:

• Creates permanent route to destination network
• Routes never change unless manually reconfigured

Steps:

1. Destination network (example: 10.0.0.0)
2. Subnet mask (example: 255.255.255.0)
3. Next-hop IP (example: 192.168.1.1)

Example:

? Destination network: 10.2.0.0
? Subnet mask: 255.255.0.0
? Next-hop IP: 192.168.1.2
✓ Static route: 10.2.0.0/255.255.0.0 via 192.168.1.2

Show Route Table

Path: Routing → Show Route Table

What it displays:

• Type of route (S = static, O = OSPF, B = BGP)
• Network address and mask
• Next-hop gateway IP

Example:

  S    10.2.0.0          255.255.0.0         via 192.168.1.2
  S    10.3.0.0          255.255.255.0       via 192.168.1.3
  O    10.4.0.0          255.255.255.0       [110/1]

Configure OSPF

Path: Routing → Configure OSPF

What it does:

• Enables dynamic routing via OSPF protocol
• Automatically discovers and updates routes
• Single configuration adds one network to OSPF

Steps:

1. OSPF Process ID (number, example: 1)
2. Network address (example: 10.0.0.0)
3. Wildcard mask (inverse netmask, example: 0.0.0.255)
4. Area ID (usually 0 for backbone area)

Example:

? OSPF Process ID: 1
? Network: 10.0.0.0
? Wildcard mask: 0.0.0.255
? Area ID: 0
✓ OSPF process 1 — network 10.0.0.0 0.0.0.255 area 0

Wildcard mask quick reference:

• /24 (255.255.255.0) → wildcard 0.0.0.255
• /16 (255.255.0.0) → wildcard 0.0.255.255
• /8 (255.0.0.0) → wildcard 0.255.255.255

Configure BGP

Path: Routing → Configure BGP

What it does:

• Enables Border Gateway Protocol for inter-AS routing
• Requires AS number assignment

Steps:

1. Local ASN (1–65535, example: 65001)
2. Remote neighbor IP (example: 203.0.113.1)
3. Remote neighbor ASN (example: 65000)

Example:

? Local ASN: 65001
? Neighbor IP: 203.0.113.1
? Neighbor ASN: 65000
✓ BGP 65001 neighbor 203.0.113.1 (remote AS 65000)

ASN ranges:

• Public: 1–64495
• Private: 64512–65534

Switching & VLANs

Configure VLANs, trunks, and access ports.

Create VLAN

Path: Switching → Create VLAN

Steps:

1. VLAN ID (1–4094, typically 1–100)
2. VLAN name (descriptive text, example: Sales)

Example:

? VLAN ID to create: 20
? VLAN name: Sales Dept
✓ VLAN 20 (Sales Dept) created.

Delete VLAN

Path: Switching → Delete VLAN

Steps:

1. Select VLAN ID to remove
2. VLAN is immediately deleted

Note: Cannot delete VLAN 1 (default VLAN).

Show VLAN Status

Path: Switching → Show VLAN Status

What it displays:

• All created VLANs
• VLAN IDs and names
• Status (active/suspended)

Example output:

  ID      Name                Status
  ────────────────────────────────────
  1       default             active
  10      Management          active
  20      Sales Dept          active
  30      Engineering         active

Set Interface to Trunk Mode

Path: Switching → Set Trunk Mode

What it does:

• Converts access port to trunk port
• Trunk ports carry traffic for multiple VLANs

Steps:

1. Select interface (example: Gi0/0)
2. Confirm setting to trunk mode

Example:

? Select interface: Gi0/0
✓ Gi0/0 set to trunk mode.

When to use: Connections between switches or multilayer switches.

Set Interface to Access Mode

Path: Switching → Set Access Mode

What it does:

• Converts trunk port to access port
• Access ports belong to single VLAN

Steps:

1. Select interface
2. Select VLAN for access mode

Example:

? Select interface: Fa1/0
? VLAN for access mode: 20
✓ Fa1/0 set to access mode, VLAN 20.

When to use: End-user device connections (computers, phones, printers).

Security

Configure ACLs, SSH, and user management.

Add ACL Rule

Path: Security → Add ACL

Steps:

1. ACL type: standard or extended
2. ACL number (numeric identifier)
3. Action: permit or deny
4. Source IP address
5. Destination IP (extended only)

Standard ACL Example:

? ACL type: standard
? ACL number: 10
? Action: permit
? Source IP: 192.168.1.0
✓ ACL 10: permit 192.168.1.0

Extended ACL Example:

? ACL type: extended
? ACL number: 100
? Action: deny
? Source IP: 10.1.5.0
? Destination IP: 172.16.0.0
✓ ACL 100: deny 10.1.5.0 → 172.16.0.0

When to use:

• Standard ACL: Filter by source IP only
• Extended ACL: Filter by source, destination, and protocol

Show All ACLs

Path: Security → Show ACLs

What it displays:

• All configured ACL entries
• Type (standard/extended)
• ACL number, action, source, destination IPs

Example output:

  standard  10      permit   192.168.1.0
  extended  100     deny     10.1.5.0 → 172.16.0.0
  extended  100     permit   any → any

Enable SSH

Path: Security → Enable SSH

What it does:

• Enables secure remote access
• Activates RSA encryption (simulated)
• SSH available on VTY lines 0–4

Steps:

1. Select "Enable SSH"
2. Wait for confirmation

Result:

✓ SSH enabled on VTY lines 0–4 (RSA key simulated).

Note: Telnet not available; SSH is secure replacement.

Add User Account

Path: Security → Add User Account

What it does:

• Creates local user for device access
• Assigns privilege level (1–15)

Steps:

1. Username (example: admin)
2. Password (example: Cisco123!)
3. Privilege level (typically 15 for admin, 1 for read-only)

Example:

? Username: networkadmin
? Password: SecureP@ss1
? Privilege level: 15
✓ User networkadmin created (privilege 15).

Show User Accounts

Path: Security → Show User Accounts

What it displays:

• All configured local users
• Privilege levels
• Status

Example output:

  networkadmin     privilege 15
  readonly         privilege 1
  auditor          privilege 5

Monitoring & Diagnostics

Test connectivity and view system logs.

Ping Target

Path: Monitoring → Ping

What it does:

• Tests reachability to target IP
• Sends 5 test packets
• Shows response time (RTT) for each

Steps:

1. Enter target IP address

Example output:

  PING 10.1.1.1 — 5 packets:
  ✓ Reply from 10.1.1.1: bytes=64 time=1.23ms TTL=64
  ✓ Reply from 10.1.1.1: bytes=64 time=0.87ms TTL=64
  ✓ Reply from 10.1.1.1: bytes=64 time=1.05ms TTL=64
  ✓ Reply from 10.1.1.1: bytes=64 time=0.92ms TTL=64
  ✓ Reply from 10.1.1.1: bytes=64 time=1.18ms TTL=64

Interpretation:

• ✓ (green) = Packet successfully received
• . (red) = Timeout, no response
• time= = Round-trip delay in milliseconds

Traceroute to Target

Path: Monitoring → Traceroute

What it does:

• Shows the path packets take to reach destination
• Lists each hop (router) along the route
• Shows latency for each hop

Steps:

1. Enter target IP address

Example output:

  Traceroute to 10.4.1.1 (max 8 hops):
   1  10.0.1.1             1.23 ms
   2  10.0.2.1             2.45 ms
   3  10.0.3.1             3.67 ms
   4  10.4.1.1             4.12 ms

Reading traceroute:

• 1, 2, 3, 4 = hop number
• IP address = router IP at that hop
• ms = round-trip time to that hop

Show System Logs

Path: Monitoring → Show Logs

What it displays:

• System events and activities
• Timestamps
• Log severity levels

Example output:

  [10:23:45] Configuration change: interface Gi0/0 set to up
  [10:24:12] ACL 10 created: permit 192.168.1.0
  [10:25:33] OSPF process 1 enabled
  [10:26:01] VLAN 20 created: Sales Dept

Use for: Auditing recent changes and troubleshooting issues.

QoS & Services

Configure Quality of Service policies and DHCP.

Add QoS Policy

Path: QoS / Services → Add QoS Policy

What it does:

• Creates traffic classification and prioritization rule
• Marks traffic with DSCP value
• Allocates bandwidth

Steps:

1. Class-map name (example: VoIP, Video, BestEffort)
2. DSCP marking (predefined values):
   • ef — Expedited Forwarding (voice, video)
   • af11, af21, af31, af41 — Assured Forwarding
   • cs1, cs2, cs3 — Class Selector
   • default — Best effort
3. Bandwidth in Kbps (example: 1000)

Example:

? Class-map name: VoIP Traffic
? DSCP marking: ef
? Bandwidth (kbps): 5000
✓ QoS rule: class VoIP Traffic dscp ef bandwidth 5000kbps

Common DSCP values:

• EF (46): Real-time voice/video
• AF41: Interactive video
• AF21: Transactional data
• Default: General IP traffic

Show QoS Policies

Path: QoS / Services → Show QoS Policies

What it displays:

• All configured QoS rules
• Class names, DSCP values, bandwidth allocation

Example output:

  Class              DSCP        BW (kbps)
  ─────────────────────────────────────
  VoIP Traffic      ef          5000
  Video Streaming   af41        10000
  BestEffort        default     1000

Configure DHCP Pool

Path: QoS / Services → Configure DHCP

What it does:

• Creates DHCP address pool for subnet
• Automatically assigns IPs to clients

Steps:

1. Pool name (example: LAN1, Guest)
2. Network address (example: 192.168.1.0)
3. Subnet mask (example: 255.255.255.0)
4. Default gateway IP (example: 192.168.1.1)
5. DNS servers (space-separated, example: 8.8.8.8 1.1.1.1)

Example:

? Pool name: Sales_LAN
? Network address: 192.168.10.0
? Subnet mask: 255.255.255.0
? Default gateway: 192.168.10.1
? DNS servers: 8.8.8.8 1.1.1.1
✓ DHCP pool Sales_LAN configured
   - Network: 192.168.10.0/255.255.255.0
   - Gateway: 192.168.10.1
   - DNS: 8.8.8.8, 1.1.1.1

Show DHCP Pools

Path: QoS / Services → Show DHCP Pools

What it displays:

• All configured DHCP pools
• Network ranges, gateways, DNS servers

Example output:

  Pool           Network            Gateway        DNS Servers
  ─────────────────────────────────────────────────────────────
  Sales_LAN      192.168.10.0/24    192.168.10.1   8.8.8.8
  Guest          192.168.50.0/24    192.168.50.1   1.1.1.1

Docker Usage

Run the simulator in a containerized environment.

Build Docker Image

Steps:

1. Navigate to project directory
2. Build image:

   docker build -t cisco-cli .

3. Wait for build to complete (2–5 minutes)

Run Container

Interactive Mode (recommended):

docker run -it cisco-cli

What -it means:

• -i = Interactive (keep stdin open)
• -t = Allocate pseudo-terminal

Named Container:

docker run -it --name my-cisco-cli cisco-cli

Background Mode:

docker run -d --name cisco-cli cisco-cli

Stop Container

Stop gracefully:

docker stop my-cisco-cli

Force stop:

docker kill my-cisco-cli

Remove Container/Image

Remove container:

docker rm my-cisco-cli

Remove image:

docker rmi cisco-cli

Troubleshooting

Issue: Commands not appearing in menu

Cause: Scroll position in menu.

Solution:

• Use arrow keys to navigate through all menu items
• Some options may be below the visible area
• Page down to see more items

Issue: Configuration lost after exit

Cause: Configuration not saved.

Solution:

1. Before exiting, go to Device Management
2. Select Save Configuration
3. Wait for "Configuration saved to NVRAM"
4. Exit normally

Issue: Interface won't set to up

Cause: IP address not assigned.

Solution:

1. Go to Interfaces
2. Select Configure Interface
3. Assign IP address and subnet mask
4. Interface automatically sets to up

Issue: Static route not appearing in table

Cause: Route not added correctly.

Solution:

1. Routing → Add Static Route
2. Verify entries:
   • Destination network (e.g., 10.0.0.0)
   • Subnet mask (e.g., 255.255.255.0)
   • Next-hop IP should be reachable
3. View with Show Route Table

Issue: OSPF network not showing

Cause: OSPF not enabled or network not added.

Solution:

1. Go to Routing → Configure OSPF
2. Enter OSPF Process ID (e.g., 1)
3. Add network(s) with wildcard masks
4. Verify with Show Route Table (routes appear as O)

Issue: SSH won't enable

Cause: Device state issue or syntax error.

Solution:

1. Security → Enable SSH
2. Confirm success message appears
3. To verify: View running config

Issue: Cannot create VLAN

Cause: VLAN ID outside valid range.

Solution:

• Valid VLAN ID range: 1–4094
• Reserved: VLAN 1 (default), VLANs 1002–1005 (Token Ring)
• Usable for practice: 10–100

Issue: ACL not filtering traffic

Cause: ACL created but not applied to interface.

Solution:

1. Go to Security → Add ACL to create rule
2. Rules are stored but not active until applied
3. View with Show ACLs to confirm creation

Issue: Ping shows "Request timed out"

Cause: Target unreachable or not configured.

Solution:

1. Verify target IP in your network
2. Check interface status: Interfaces → Show Interface Status
3. Check routing table: Routing → Show Route Table
4. Try local IP first to test

Issue: Docker container exits immediately

Cause: Process terminated or error in startup.

Solution:

1. Check logs:

   docker logs <container-id>

2. Use interactive mode:

   docker run -it cisco-cli

3. Verify Node.js installed in container

Issue: Cannot connect to container

Cause: Container not running or port not exposed.

Solution:

1. Check running containers:

   docker ps

2. Start if not running:

   docker run -it cisco-cli

3. Verify no errors in startup

Tips & Best Practices

Organize Your Config

1. Build incrementally:

   • First: Configure basic interfaces
   • Then: Add static routes or routing protocols
   • Finally: Add security policies

2. Document with descriptions:

   • Always set interface descriptions
   • Name VLANs semantically (e.g., Sales, Management)
   • Use meaningful class names for QoS

3. Save frequently:

   • Save after each major change
   • Save before testing potentially breaking changes
   • Reload to test startup config

Testing Workflow

1. Configure interfaces and IP addresses
2. Add routing (static or dynamic)
3. Test with Ping and Traceroute
4. Review with Show commands
5. Save configuration
6. Reload to verify persistence

Common Config Scenarios

Scenario 1: Basic LAN Setup

• Create VLAN 10 (LAN)
• Assign interface Gi0/0 to VLAN 10, IP: 192.168.1.1/24
• Create DHCP pool for 192.168.1.0/24
• Enable SSH for remote access
• Save configuration

Scenario 2: Multi-Router Network

• Configure each router with unique IP on inter-router links
• Add static routes to all networks
• Test with Ping/Traceroute
• Replace with OSPF for dynamic routing

Scenario 3: Security Policy

• Create standard ACL to permit trusted subnets
• Create extended ACL to deny specific traffic patterns
• Add SSH, disable Telnet
• Create local users with privilege levels
• View logs to audit access

Keyboard Shortcuts & Tips

| Key | Function | | ------ | ----------------------------------- | | ↑ / ↓ | Navigate menu items | | ← / → | Scroll (some lists) | | Enter | Select item | | Ctrl+C | Exit current menu (returns to main) | | Q | Quit application | | Ctrl+L | Clear screen (terminal) |

Common Commands Reference

| Task | Location | | ----------------- | --------------------------------------- | | View device info | Device Management → Show Version | | Show all config | Device Management → Show Running Config | | Save changes | Device Management → Save Configuration | | Set IP address | Interfaces → Configure Interface | | Add route | Routing → Add Static Route | | Create VLAN | Switching → Create VLAN | | Add firewall rule | Security → Add ACL | | Enable SSH | Security → Enable SSH | | Test connectivity | Monitoring → Ping | | View logs | Monitoring → Show Logs | | Add QoS class | QoS / Services → Add QoS Policy |

Getting Help

• GitHub Issues: Report bugs at cisco-cli/issues
• License: MIT — see LICENSE file

Version: 1.0.0
Last Updated: 2026
Maintainer: Girish Kor