Metrics

RSSAC002v5 defines six metrics. We publish the four that describe the DNS traffic our servers receive:

Metric	What it measures
`traffic-volume`	Queries received and responses sent, split by IPv4/IPv6 and UDP/TCP
`traffic-sizes`	Distribution of query and response sizes
`rcode-volume`	Responses per DNS response code (RCODE), such as `NOERROR` and `NXDOMAIN`
`unique-sources`	Distinct IP addresses that sent queries

We don't publish the other two, zone-size and load-time. For the size of the .nl zone, see the SIDN Labs statistics site.

Each file covers one day, starting at 00:00 UTC.

Combined and per-server files

Every metric is published twice: once for all .nl authoritative servers combined, and once per server.

nl-rssac002/
└── 2026/03/
    └── unique-sources/
        ├── nl-20260310-unique-sources.yaml          ← all servers
        └── nameservers/
            ├── nl-ns1.dns.nl-20260310-unique-sources.yaml
            ├── nl-ns3.dns.nl-20260310-unique-sources.yaml
            └── nl-ns4.dns.nl-20260310-unique-sources.yaml

All servers combined

The file in the metric folder covers all three servers. For example, nl-20260310-unique-sources.yaml counts the unique IP addresses that queried any of them on 10 March 2026:

version: rssac002v5
service: nl_servers
metric: unique-sources
start-period: '2026-03-10T00:00:00+00:00'
num-sources-ipv4: 1542672
num-sources-ipv6: 283085
num-sources-ipv6-aggregate: 131897

Field	Meaning
`service`	Which servers the numbers cover. `nl_servers` means all of them.
`start-period`	Start of the day covered, in UTC.
`num-sources-ipv4`	Unique IPv4 addresses.
`num-sources-ipv6`	Unique IPv6 addresses.
`num-sources-ipv6-aggregate`	Unique IPv6 `/64` prefixes. One network often uses many addresses within a single `/64`, so this is a better estimate of the number of networks.

Per server

The nameservers subfolder holds the same metric for each server. For example, nl-ns1.dns.nl-20260310-unique-sources.yaml covers only ns1.dns.nl:

version: rssac002v5
service: nl_servers-ns1.dns.nl
metric: unique-sources
start-period: '2026-03-10T00:00:00+00:00'
num-sources-ipv4: 1315375
num-sources-ipv6: 224628
num-sources-ipv6-aggregate: 103879

Adding up per-server files: query counts, such as traffic-volume, add up across servers. Unique-source counts don't: an IP address that queries several servers appears in each server's file, but only once in the combined file.

Comparison with the Root Servers

Each Root Server operator publishes RSSAC-002 metrics only for the Root Server it runs. For example, USC/ISI publishes the metrics for B-Root. To see all Root Servers side by side, use the RSSAC002 dashboard.

For .nl, we publish both levels ourselves: each server on its own, and all servers combined.