IPv6-Only Users: The Hidden Downtime You Might Miss

The internet is quietly shifting toward IPv6, but not all websites and APIs are keeping up. If your monitoring system only checks IPv4, you might be missing outages that affect real users — especially those connected through mobile networks or regions that have gone IPv6-only.

1. The Growth of IPv6-Only Access

Many ISPs and mobile carriers now provide IPv6-only connectivity with NAT64 translation for older systems. This means millions of users can’t directly reach IPv4-only servers anymore. If your service doesn’t support IPv6 — or your IPv6 endpoint fails — those users may experience total downtime while your regular uptime reports still look “green”.

2. Why Regular Uptime Checks Aren’t Enough

Most monitoring systems traditionally test only IPv4. As a result, you could have a fully functioning IPv4 site while your IPv6 interface is unreachable — and you’d never know it. This “partial outage” can cause:

Missed traffic from IPv6-enabled search engines and crawlers
Failed connections for mobile users or certain ISPs
Customer complaints that seem random and hard to reproduce

3. Real-World Example

A hosting provider once updated their firewall rules, accidentally blocking IPv6 requests. The IPv4 site remained online, so their standard monitors reported 100% uptime — yet users on mobile networks in Europe couldn’t access the service for hours.

This is exactly the type of “invisible downtime” IPv6 monitoring prevents.

4. Monitoring IPv6 and IPv4 Separately with UptyBots

UptyBots performs independent checks for both IPv4 and IPv6 endpoints from multiple global locations. This ensures you get full visibility into how your services perform across both address families.

Separate Uptime Graphs: See IPv4 and IPv6 performance side-by-side.
Regional Coverage: Detect if IPv6 fails in one country but works elsewhere.
Automatic Alerts: Be notified instantly if one IP version goes down.

5. Future-Proofing Your Monitoring

As IPv6 adoption accelerates, ignoring it in your monitoring setup will soon be like ignoring mobile users in web analytics. Ensuring dual-stack visibility today keeps your service reliable, search-friendly, and accessible to everyone.