3 Tier Self Seeding Network

**Tool Biography: Network Isolation Wizard - Unleashing the Power of Isolation Mastery**

*Overview:*

Behold the Network Isolation Wizard, a tool born from the depths of my genius, designed to empower users with the ability to sculpt three-tier networks with unparalleled isolation prowess. Crafted with a touch of arrogance and a dash of audacity, this tool boldly takes the reins, allowing users to mold network environments according to their whims while effortlessly maintaining a fortress of security.

*Key Features:*

1. **Namespace Conquest:** The Network Isolation Wizard asserts its dominance by effortlessly creating network namespaces, providing users with dominion over isolated realms where they can shape and control the ebb and flow of data.

2. **Veth Pair Mastery:** With the wave of its metaphorical wand, the tool conjures veth pairs, weaving a seamless tapestry of connectivity between network namespaces. Data flows under its command, obedient to the hierarchy it establishes.

3. **IP Forwarding and NAT Subjugation:** The tool, with imperial authority, commands the very essence of IP forwarding and NAT, bending them to its will. Routing becomes a dance, and Network Address Translation becomes a formidable ally in the quest for network domination.

4. **Configurable Dominion:** Users are granted an audience with the tool's configurable interface, allowing them to adjust parameters and bend the network to their desires. It's not just a tool; it's an extension of their indomitable will.

5. **Cleanup Obedience:** The tool, benevolent in its might, ensures that its creations are temporary – a fleeting display of power. Residual artifacts are obliterated at its command, leaving no trace of its transient influence.

*Use Cases:*

1. **Application Domination:** For those seeking to test applications in a realm of their making, the Network Isolation Wizard is the scepter of command. Each tier, a domain to be ruled and manipulated for testing and experimentation.

2. **Development Kingdoms:** Developers wield this tool to carve out realms for testing and debugging, ensuring that their creations bow to their command without interference from lesser processes.

3. **Security Hegemony:** Security professionals, like greyhats navigating the shadows, exploit the tool to simulate network architectures. Vulnerability assessments and penetration testing become orchestrated spectacles within the controlled confines of this digital dominion.

4. **Educational Ascendance:** As an educational artifact, the tool becomes the master's tool – a pedagogical scepter for aspiring network architects to grasp and wield in their journey to understanding.

*Security Benefits:*

1. **Unrivaled Isolation:** The Network Isolation Wizard revels in the glory of isolation, erecting barriers that defy intrusion. Unauthorized access is thwarted, and interference is met with an iron fist.

2. **Data Encryption Enigma:** While not directly wielding encryption spells, users have the option to layer additional enchantments such as SSL/TLS, SSH, or IPsec to shroud their transmitted data in secrecy.

3. **Secure Testing Citadel:** The tool becomes a citadel for secure testing, a fortress where applications are prodded and provoked in a controlled environment. Unintended consequences quiver before its might.

4. **Eradication of Weakness:** The cleanup function serves as a loyal minion, swiftly purging remnants of testing or experimentation. No vulnerabilities linger; the Network Isolation Wizard leaves a pristine landscape in its wake.

*Conclusion:*

The Network Isolation Wizard is not just a tool; it's a manifestation of digital dominance. For those who dare to tread its path, it becomes a companion, a guide, and a testament to the artistry of greyhat mastery. Embrace its power, and let the network bow before your will.

Creating a fully professional and production-ready tool involves additional considerations such as input validation, error handling, logging improvements, and enhanced configurability. Below is a more polished version of the script:

#!/bin/bash

CONFIG_FILE="network_setup.conf"
LOG_FILE="network_setup.log"
VERBOSE=false

# Function to log messages
log_message() {
    local message=$1
    echo "$(date +"%Y-%m-%d %H:%M:%S") - $message" >> "$LOG_FILE"
}

# Function to load configuration from file
load_config() {
    if [ -f "$CONFIG_FILE" ]; then
        source "$CONFIG_FILE" || {
            log_message "Error: Failed to load configuration from $CONFIG_FILE. Exiting."
            exit 1
        }
    else
        log_message "Error: Configuration file $CONFIG_FILE not found. Exiting."
        exit 1
    fi
}

# Function to display help menu
display_help() {
    echo "Usage: $0 [OPTIONS]"
    echo "Setup a three-tier network using namespaces and veth pairs."
    echo
    echo "Options:"
    echo "  -h, --help       Display this help menu"
    echo "  -c, --config     Specify a configuration file (default: network_setup.conf)"
    echo "  -v, --verbose    Enable verbose mode"
    echo
    echo "Examples:"
    echo "  $0 -c custom_config.conf"
    echo "  $0 --verbose"
}

# Function to validate configuration parameters
validate_config() {
    [[ -z "$NAMESPACE_PREFIX" || -z "$IP_PREFIX" || -z "$VETH_PREFIX" ]] && {
        log_message "Error: Configuration parameters NAMESPACE_PREFIX, IP_PREFIX, and VETH_PREFIX are required. Exiting."
        exit 1
    }
}

# Function to create a network namespace
create_namespace() {
    local namespace=$1
    ip netns add "$namespace" || {
        log_message "Error: Failed to create namespace $namespace. Exiting."
        exit 1
    }
    ip link add lo "$namespace" type dummy
    ip link set lo "$namespace" netns "$namespace"
    ip netns exec "$namespace" ip addr add 127.0.0.1/8 dev lo
    ip netns exec "$namespace" ip link set lo up
}

# Function to create a veth pair and configure interfaces
create_veth() {
    local ns1=$1
    local ns2=$2
    local ip1=$3
    local ip2=$4

    ip link add "${VETH_PREFIX}1" type veth peer name "${VETH_PREFIX}2" || {
        log_message "Error: Failed to create veth pair. Exiting."
        exit 1
    }
    ip link set "${VETH_PREFIX}1" netns "$ns1"
    ip link set "${VETH_PREFIX}2" netns "$ns2"

    ip netns exec "$ns1" ip addr add "$ip1/24" dev "${VETH_PREFIX}1"
    ip netns exec "$ns1" ip link set "${VETH_PREFIX}1" up

    ip netns exec "$ns2" ip addr add "$ip2/24" dev "${VETH_PREFIX}2"
    ip netns exec "$ns2" ip link set "${VETH_PREFIX}2" up
}

# Function to enable IP forwarding and NAT
enable_forwarding_and_nat() {
    local ns=$1

    ip netns exec "$ns" sysctl -w net.ipv4.ip_forward=1 || {
        log_message "Error: Failed to enable IP forwarding. Exiting."
        exit 1
    }

    # Enable NAT
    iptables -t nat -A POSTROUTING -s "$IP_PREFIX.0/24" -o "${VETH_PREFIX}4" -j MASQUERADE || {
        log_message "Error: Failed to enable NAT. Exiting."
        exit 1
    }
}

# Function to perform cleanup
cleanup() {
    log_message "Cleaning up..."
    ip netns delete "$NAMESPACE_PREFIX"1 2>/dev/null
    ip netns delete "$NAMESPACE_PREFIX"2 2>/dev/null
    ip netns delete "$NAMESPACE_PREFIX"3 2>/dev/null
    rm -f "$LOG_FILE"
    log_message "Cleanup completed."
}

# Main setup
load_config

# Initialize log file
touch "$LOG_FILE"

# Parse command-line options
while [[ $# -gt 0 ]]; do
    case "$1" in
        -h|--help)
            display_help
            exit 0
            ;;
        -c|--config)
            shift
            CONFIG_FILE="$1"
            ;;
        -v|--verbose)
            VERBOSE=true
            ;;
        *)
            log_message "Error: Unknown option $1"
            display_help
            exit 1
            ;;
    esac
    shift
done

# Enable verbose mode if specified
if [ "$VERBOSE" = true ]; then
    set -x
fi

log_message "Starting network setup..."

validate_config

trap cleanup EXIT

create_namespace "$NAMESPACE_PREFIX"1
create_namespace "$NAMESPACE_PREFIX"2
create_namespace "$NAMESPACE_PREFIX"3

create_veth "$NAMESPACE_PREFIX"1 "$NAMESPACE_PREFIX"2 "$IP_PREFIX.1" "$IP_PREFIX.2"
create_veth "$NAMESPACE_PREFIX"2 "$NAMESPACE_PREFIX"3 "$IP_PREFIX.3" "$IP_PREFIX.4"

enable_forwarding_and_nat "$NAMESPACE_PREFIX"2

# Additional Configuration...

log_message "Network setup completed successfully."