IPv6 Response Time

What This Check Does

The IPv6 Response Time check measures the DNS query response time for each of your active nameservers over IPv6. If any nameserver takes longer than 150 milliseconds to respond via IPv6, or fails to respond at all, this check fails.

DNS Spy sends timed DNS queries to each nameserver via IPv6 and records the response time. This check only applies to nameservers that have AAAA records.

Why It Matters

As IPv6 adoption grows, an increasing number of DNS queries are sent over IPv6. If your nameservers respond slowly over IPv6 while performing well over IPv4, users on IPv6-preferred networks will experience degraded performance. This can be particularly impactful in regions with high IPv6 adoption, including many mobile networks.

IPv6 response times can differ from IPv4 for various reasons: different network paths, misconfigured IPv6 routing, or nameserver software that handles IPv6 queries less efficiently. Monitoring IPv6 response times separately ensures you catch IPv6-specific performance issues.

NIST SP 800-81, Section 3.2, recommends monitoring DNS performance across all protocols. DNS Spy's IPv6-specific response time monitoring helps ensure your DNS infrastructure performs well for all users.

NIST SP 800-81 Compliance

Section 3.2 of the NIST Secure DNS Deployment Guide covers DNS performance monitoring. As IPv6 becomes mandatory in many government and enterprise environments, monitoring IPv6 DNS performance is increasingly important for NIST compliance.

Good vs. Bad Configuration

Bad Configuration

ns1.example.com responds in 40ms over IPv4 but 220ms over IPv6 due to suboptimal IPv6 routing. IPv6 users experience noticeably slower DNS resolution.

Good Configuration

All nameservers respond in under 100ms over both IPv4 and IPv6. ns1.example.com: 35ms (IPv4), 42ms (IPv6). Consistent performance across both protocols.

How DNS Spy Monitors This

DNS Spy sends timed DNS queries to each nameserver over IPv6 during every monitoring cycle. Response times are measured and compared against the 300ms threshold. Alerts are triggered for slow or unresponsive nameservers. The dashboard provides separate IPv4 and IPv6 response time graphs, making it easy to identify protocol-specific performance issues.