dead-cdn-dns-bypass

Dead CDN DNS Bypass - Recovering Content from Defunct Services

Problem

When a service shuts down, their DNS records stop resolving, making URLs appear completely dead. However, the actual content often still exists on CDN servers (Fastly, CloudFront, Akamai, etc.) that continue serving it - the servers just aren't reachable via normal DNS resolution.

Context / Trigger Conditions

• Service has shut down (Vine, defunct startups, etc.)
• Original CDN URLs return DNS resolution errors
• Content was hosted on a major CDN provider
• You need to recover/archive historical content
• Wayback Machine doesn't have the specific content

Solution

Step 1: Identify the CDN Provider

Look at the original URL hostname to identify the CDN:

• *.cdn.vine.co → Fastly
• *.cloudfront.net → AWS CloudFront
• *.akamaized.net → Akamai
• *.fastly.net → Fastly

Step 2: Find CDN IP Addresses

For Fastly (common for many defunct services):

# Fastly's anycast IPs
151.101.1.6
151.101.65.6
151.101.129.6
151.101.193.6

For other CDNs, check their documentation or try known IP ranges.

Step 3: Test with Host Header

# Test if content is still served
curl -sI \
  -H "Host: original-cdn-hostname.com" \
  "http://FASTLY_IP/path/to/content"

# Example for Vine:
curl -sI \
  -H "Host: mtc.cdn.vine.co" \
  "http://151.101.1.6/r/videos/ABC123.mp4"

Step 4: Download Content

import requests

def download_via_cdn_ip(original_url: str, cdn_ip: str) -> bytes:
    """Download content bypassing dead DNS."""
    import re

    # Extract host and path from URL
    match = re.match(r'https?://([^/]+)(/.+)', original_url)
    if not match:
        return None

    host = match.group(1)
    path = match.group(2)

    # Hit IP directly with Host header
    response = requests.get(
        f"http://{cdn_ip}{path}",
        headers={"Host": host},
        timeout=30
    )

    if response.status_code == 200:
        return response.content
    return None

# Example usage
content = download_via_cdn_ip(
    "http://mtc.cdn.vine.co/r/videos/ABC123.mp4",
    "151.101.1.6"
)