IPv4 Response Time

What This Check Does

The IPv4 Response Time check measures the DNS query response time for each of your active nameservers over IPv4. If any nameserver takes longer than 150 milliseconds to respond, or fails to respond at all, this check fails.

DNS Spy sends timed DNS queries to each nameserver via IPv4 and records the response time. The 300ms threshold is based on industry best practices for acceptable DNS performance.

Why It Matters

DNS resolution is the first step in every web request. Before a user's browser can connect to your website, it must resolve your domain name to an IP address. Slow DNS response times directly increase page load times and can create a cascading effect on performance. A 300ms+ DNS response time means users wait at least that long before the connection even begins.

Research shows that even 100ms of additional latency can reduce conversion rates by 7%. For e-commerce sites, slow DNS can directly impact revenue. Nameserver response times can degrade due to overloaded servers, network congestion, geographic distance, or misconfiguration.

NIST SP 800-81, Section 3.2, addresses DNS performance requirements and recommends monitoring response times as part of DNS infrastructure management. DNS Spy helps ensure your nameservers meet performance benchmarks.

NIST SP 800-81 Compliance

Section 3.2 of the NIST Secure DNS Deployment Guide covers DNS performance, including the importance of responsive nameservers. Regular monitoring of response times, as DNS Spy provides, is aligned with NIST's recommendations for maintaining efficient DNS infrastructure.

Good vs. Bad Configuration

Bad Configuration

ns1.example.com responds in 45ms over IPv4, but ns2.example.com responds in 280ms. The slow nameserver degrades the experience for any resolver that queries it.

Good Configuration

All nameservers respond in under 100ms over IPv4. ns1.example.com: 35ms, ns2.example.com: 42ms, ns3.example.com: 38ms. Consistent, fast response times across all nameservers.

How DNS Spy Monitors This

DNS Spy sends timed DNS queries to each nameserver over IPv4 during every monitoring cycle. Response times are recorded and compared against the 300ms threshold. If any nameserver exceeds this threshold or fails to respond, an alert is triggered. Historical response time data is graphed on the dashboard, helping you identify performance trends and degradation patterns.