Traceroute Program in Python

Overview

This project is a Python-based implementation of the traceroute network diagnostic tool. It utilizes ICMP (Internet Control Message Protocol) packets to trace the path that packets take to a destination. The program also calculates round-trip times (RTT), detects packet loss, and displays network hops along the route to the target.

Features

• Implements ICMP echo requests to trace network routes.
• Supports time-to-live (TTL) handling for hop-by-hop analysis.
• Displays RTT (Round Trip Time) for each hop.
• Detects packet loss and reports unreachable hosts.
• Resolves IP addresses to hostnames where possible.
• Identifies ICMP response types, including TTL exceeded, unreachable destinations, and echo replies.

Installation

Prerequisites

Ensure you have Python 3.x installed on your system.

Required Dependencies

This program uses Python's built-in modules:

• socket
• struct
• time
• select

No external libraries are required.

Usage

To use the traceroute program, run the script from the terminal:

python traceroute.py

By default, the script contains example target hosts. To modify the target, change the following line in main():

icmpHelperPing.traceRoute("www.google.com")

Alternatively, you can trace routes to an IP address:

icmpHelperPing.traceRoute("8.8.8.8")

How It Works

1. Packet Construction: The program builds an ICMP Echo Request packet with a unique identifier and sequence number.
2. Sending Requests: The script sends ICMP packets with increasing TTL values (starting at 1).
3. Interpreting Responses:
   • If a router along the way returns a TTL exceeded message, the hop is recorded.
   • If the target host responds with an ICMP Echo Reply, the route is complete.
   • If a destination unreachable message is received, the path is blocked.
4. Displaying Results: The program prints each hop’s IP, hostname (if available), RTT, and response type.

Example Output

Tracing route to www.google.com:
Hop: 1    TTL=1    RTT=12 ms    Type=11    Code=0    192.168.1.1
Hop: 2    TTL=2    RTT=24 ms    Type=11    Code=0    203.0.113.1
Hop: 3    TTL=3    RTT=36 ms    Type=0    Code=0    8.8.8.8 [google.com]
Trace complete.

Error Handling

• If the request times out, the program prints:

  *        *        *        *        *    Request timed out.
  

• If the destination is unreachable, the response indicates the reason (e.g., host unreachable or network unreachable).

References

This implementation was inspired by various sources:

• GeeksforGeeks Traceroute Implementation
• ICMP Parameters - IANA
• YouTube Tutorial on ICMP and Traceroute
• Packet Loss Calculation Guide

License

This project is open-source and free to use for educational and research purposes.

Author

Developed by Brett Sullivan on February 7, 2024.