Example Path: examples/VLan

VLAN Example Application

Overview

This NetBurner application demonstrates the creation and management of multiple VLAN (Virtual Local Area Network) interfaces on a single Ethernet port. The application creates three different VLAN interfaces with different configurations and provides both web-based and serial console interfaces for monitoring network status.

To build this example MULTIHOME must be enabled in predef.h. Rather than edit the system file in nbrtos/include, this example uses the SDK override feature: it ships a local overload/nbrtos/include/predef-overload.h that defines MULTIHOME (and raises NUM_MULTI_INTERFACES) just for this project. The interfaces created are:

Ethernet 0, DHCP, VLAN ID 1
Ethernet 0, DHCP, VLAN ID 2
Ethernet 0, Static IP, VLAN ID 10

The serial port interface provides an interactive menu to display interface and VLAN information, as well as other system parameters.

Features

Multiple VLAN Interface Creation: Creates 3 VLAN interfaces on Ethernet 0
Mixed Configuration Support: Supports both DHCP and static IP configurations
Interactive Serial Menu: Command-line interface for network diagnostics
Web Interface: HTTP server displaying network interface information
IPv4 and IPv6 Support: Comprehensive IP address management and display
Real-time Network Monitoring: Link status, ARP tables, and interface statistics

VLAN Configuration

The application automatically creates the following VLAN interfaces:

VLAN ID 1: Ethernet 0 with DHCP configuration
VLAN ID 2: Ethernet 0 with DHCP configuration
VLAN ID 10: Ethernet 0 with static IP (198.18.1.20/16)

Prerequisites

MULTIHOME Support: Must be enabled in predef.h
NetBurner Platform: Compatible NetBurner hardware platform
Network Infrastructure: VLAN-capable switch or router

Enabling MULTIHOME

This example already enables MULTIHOME for you with the SDK override feature, so it builds as-is. To do the same in your own project:

Create overload/nbrtos/include/predef-overload.h in your project directory
Add #define MULTIHOME to enable multiple interface support
Add any other required definitions (this example also sets #define NUM_MULTI_INTERFACES (10))

This approach overrides the system predef.h for your project only, without modifying the SDK files directly.

Serial Console Commands

The application provides an interactive serial console with the following commands:

Command	Description
A	Show ARP table
C	Show network counters
E	Dump Ethernet information
I	Show all network interfaces and IP addresses
W	Display system tick count and uptime
?	Show help menu
1-9 <vlan_id>	Set VLAN tag on interface (1-9)

Example Usage

I               # Show all interfaces
A               # Display ARP table
1 100           # Set interface 1 to VLAN 100
W               # Show system uptime

Network Interface Information

The application displays comprehensive network information including:

IPv4 Information

IP Address
Subnet Mask
DNS Servers (Primary and Secondary)
Gateway Address
Auto-IP Address

IPv6 Information (if enabled)

Link-local addresses
Router-assigned addresses
DHCP-assigned addresses
Static addresses
DNS servers with source information
DHCP lease timing information

Physical Interface Details

MAC Address
Link Status (UP/DOWN)
Link Speed (MB)
Duplex Mode (Full/Half)

Web Interface

The application includes an HTTP server that serves a single page (index.html) listing every active network interface. The page shell is a static HTML file styled with a self-contained stylesheet (plain CSS, no framework or CDN); the live per-interface data is produced on the device as the page is served.

A  tag in index.html hands the HTTP socket to showIpAddressesWeb() in ip_util.cpp, which walks the interface list and formats each value straight into the page with fdprintf, using the same hI / I IP-address specifiers as the serial output. For each interface the page shows:

MAC address, VLAN tag, and link status (speed / duplex)
IPv4 configuration: IP, mask, DNS, gateway, and Auto-IP
Clickable IP links: open the device on that interface's IPv4 (or IPv6) address
IPv6 addresses with their source (Link-Local / Router / DHCP / Static) and DHCP lease timing

Access the web interface by navigating to any of the device's IP addresses in a web browser. Reload to refresh; newly-assigned IPv6 addresses may take a few seconds to appear.

Related Examples

ShowInterfaces — web view of a single network interface
MultiHome — multiple interfaces on one device without VLAN tagging

File Structure

project/
    src/main.cpp                              # Main application logic and VLAN setup
    src/ip_util.cpp                           # IP address display helpers (serial + web)
    src/ip_util.h                             # Header file for IP utilities
    html/index.html                           # Web interface page (static shell + CPPCALL)
    html/style.css                            # Self-contained page stylesheet
    html/logo.png                             # Header logo
    overload/nbrtos/include/predef-overload.h # Enables MULTIHOME for this project

Key Functions

VLAN Management

AddVlanInterface(): Creates a new VLAN interface on a parent Ethernet port
InterfaceBlock::vlan_tag_value: The VLAN tag for an interface (set at runtime from the serial menu)

Network Information Display

showIpAddressesSerial(): Displays interface info on serial console
showIpAddressesWeb(): Generates web page with interface information
showLinkStatus(): Shows physical link status

Utility Functions

getTimeStringFromSeconds(): Converts seconds to HH:MM:SS format
getLeaseTimeInfo(): Formats DHCP lease timing information
SourceName(): Returns human-readable IPv6 address source names

Building and Deployment

Setup Project: Create new NetBurner project
Enable MULTIHOME: Add predef.h with #define MULTIHOME
Add Source Files: Include all .cpp and .h files
Build: Compile using NetBurner development tools
Deploy: Flash to NetBurner hardware

Network Setup Requirements

VLAN-Capable Switch: Network infrastructure must support VLAN tagging
Proper VLAN Configuration: Switch ports must be configured for appropriate VLAN IDs
IP Address Management: Ensure IP ranges don't conflict across VLANs

Troubleshooting

Common Issues

MULTIHOME Not Enabled: Verify predef.h contains #define MULTIHOME
Link Status Down: Check physical connections and cable
DHCP Not Working: Verify DHCP server availability on VLANs
Web Interface Inaccessible: Check IP address configuration and routing

Debug Commands

Use the serial console commands to diagnose issues:

E - Check Ethernet hardware status
I - Verify interface configuration
C - Review network counters for errors
A - Check ARP table for connectivity

Platform Compatibility

This application is designed for NetBurner embedded platforms with Ethernet capability. It supports both single and dual Ethernet configurations (commented code shows dual-port setup for platforms like the 54417).

IPv6 Support

IPv6 functionality is conditionally compiled based on the IPV6 preprocessor definition. When enabled, the application provides:

Multiple IPv6 address assignment methods
DHCP v6 lease management
Router advertisement processing
Comprehensive IPv6 status reporting