Propagation providers
Propagation providers
Cbox\Dns\Propagation\PublicResolvers is a registry of well-known public recursive
resolvers as named PublicResolver value objects, so a propagation report can read
"Google Public DNS / Cloudflare / Quad9" instead of bare IPs.
Each PublicResolver has a machine name, a human label, the ip to query, and
an optional region.
The registry
PublicResolvers::all() — the full 15-entry set used by checkAcrossProviders():
| name | label | ip | region |
|---|---|---|---|
google-primary |
Google Public DNS | 8.8.8.8 | Global (anycast) |
google-secondary |
Google Public DNS | 8.8.4.4 | Global (anycast) |
cloudflare-primary |
Cloudflare | 1.1.1.1 | Global (anycast) |
cloudflare-secondary |
Cloudflare | 1.0.0.1 | Global (anycast) |
quad9 |
Quad9 | 9.9.9.9 | Global (anycast) |
opendns-primary |
OpenDNS | 208.67.222.222 | Global (anycast) |
opendns-secondary |
OpenDNS | 208.67.220.220 | Global (anycast) |
level3-primary |
Level3 | 4.2.2.1 | Global (anycast) |
level3-secondary |
Level3 | 4.2.2.2 | Global (anycast) |
verisign |
Verisign Public DNS | 64.6.64.6 | Global (anycast) |
adguard |
AdGuard DNS | 94.140.14.14 | Global (anycast) |
dns-watch |
DNS.Watch | 84.200.69.80 | Germany |
neustar |
Neustar UltraDNS | 156.154.70.1 | Global (anycast) |
yandex |
Yandex DNS | 77.88.8.8 | Russia |
comodo |
Comodo Secure DNS | 8.26.56.26 | Global (anycast) |
PublicResolvers::default() — the lean six-entry panel (one or two per major
operator) used by PropagationChecker::check() when no wider set is requested,
kept small so a check stays fast: the two Google IPs, the two Cloudflare IPs, Quad9,
and OpenDNS primary.
What region means (and doesn't)
region is the operator's stated location, or "Global (anycast)". It is not a
geographic vantage point. Querying 8.8.8.8 from your host still exits through your
own uplink and lands on the nearest anycast PoP — so region labels the operator,
not where the lookup was answered.
This is why a multi-provider check is a cache-diversity signal across independent operators, not global geographic propagation. Geo-distributed vantage points are a documented roadmap non-goal here. See Propagation for the full honest scope.