In Amazon Route 53, TTL (Time to Live) is the amount of time (in seconds) that DNS resolvers (like Google DNS, Cloudflare DNS) cache a DNS record before checking back with Route 53 for updated information.
🔧 Why TTL Matters
| TTL Value |
Meaning |
| Higher TTL |
✅ Less DNS traffic, ✅ Better performance, ❌ Slower updates |
| Lower TTL |
✅ Faster propagation of changes, ❌ Higher query load |
📦 Where TTL Is Used
When creating or editing DNS records in Route 53 (like A, CNAME, MX, etc.), you'll specify TTL like:
📈 TTL Values in Seconds
| TTL (Seconds) |
Human Time |
Use Case |
| 60 |
1 minute |
For frequently changing endpoints |
| 300 |
5 minutes |
Standard — good balance |
| 3600 |
1 hour |
Low-change environments |
| 86400 |
24 hours |
Static sites, rarely changed records |
🧠 How TTL Works (Flow)
- User types
certifikation.com in browser
- DNS resolver checks local cache
- If valid → uses cached IP
- If expired (TTL passed) → queries Route 53 again
- Route 53 returns the IP + resets TTL in resolver’s cache
⚠️ TTL in Real Life
- You change your ELB or EC2 IP → If TTL is 1 hour, users might see old IP until cache expires
- You’re launching new features → Use a low TTL temporarily for faster DNS updates
✅ Summary
| Term |
Description |
| TTL |
Cache time for DNS records (in sec) |
| Low TTL |
Fast updates, more queries |
| High TTL |
Slow updates, fewer queries |
