CROSSFIT Exploratory Task – Latency Aware DNS Server

📌 Overview

This task is for the project CROSSFIT (Content-aware Routing Over Standard Service For Interactive Technologies) initiative.
The goal is to demonstrate a simplified authoritative DNS server that dynamically steers traffic for XR applications based on latency measurements.

Traditional DNS and BGP cannot adapt to real time performance changes. This prototype DNS server:

• Periodically measures latency to two backend servers.
• Selects the lowest latency server dynamically.
• Answers DNS queries for snl-columbia-university.github.io with that server’s IP.
• Logs all measurements, queries, and responses.

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⚙️ Features

• Active latency measurement every 10 seconds
• Returns best server IP dynamically
• Configurable DNS port via --port flag
• Logs include:
  • Ping results
  • Incoming queries
  • Outgoing responses

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Logs

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Test Result

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🖥️ Requirements

• Python 3.8+
• dnslib library

Install dependencies:

pip install dnslib

## 🚀 How to Run  

## Run on standard DNS port (requires root/sudo):  

sudo python3 crossfit_dns.py --port 53

## OR ##

## Run on custom port (no root needed, e.g., 8053):

python3 crossfit_dns.py --port 8053

## 🔧 How to Test  

## If running on port 53:

dig @127.0.0.1 snl-columbia-university.github.io

## OR ##

## If running on custom port (e.g., 8053):

dig @127.0.0.1 -p 5353 snl-columbia-university.github.io