Score DNS, DHCP, NTP, AAA and syslog health into one weighted grade and flag the weakest service.
Each core service is scored against the threshold at which users start noticing it, then weighted by how completely its failure blocks access. DNS carries the largest weight because nothing else works without it, and AAA is close behind because a failed authentication denies the network outright. Core services fail quietly until they fail totally, so a single rolled-up grade with a weakest-service pointer gives operations somewhere to look before the pool exhausts or the clock skew breaks Kerberos.
Infrastructure Services Health Score
score = 0.30 × DNS + 0.20 × DHCP + 0.20 × AAA + 0.15 × NTP + 0.15 × syslog, each normalised to 0–100.
score = 0.30 × DNS + 0.20 × DHCP + 0.20 × AAA + 0.15 × NTP + 0.15 × syslog, each normalised to 0–100. Each core service is scored against the threshold at which users start noticing it, then weighted by how completely its failure blocks access. DNS carries the largest weight because nothing else works without it, and AAA is close behind because a failed authentication denies the network outright.
Core services fail quietly until they fail totally, so a single rolled-up grade with a weakest-service pointer gives operations somewhere to look before the pool exhausts or the clock skew breaks Kerberos.
This calculator takes 5 inputs: DNS query success rate, DHCP pool utilisation, NTP offset from reference, AAA response latency, Syslog message drop rate. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
Pools do not fail gracefully — once utilisation passes about 70% normal daily variation and lease overhang start producing intermittent failures for a subset of clients, which is far harder to diagnose than outright exhaustion.