Is transit the default path?

No. Peering in Miami is default; transit to São Paulo is overflow and is billed that way.

Does DNS on letter D share fate with other letters?

The control plane is shared. Data-plane queues for DNS stay isolated, so incident d-01 cannot drain neighbor letters.

DNS: docs in Miami (MIA) · D-12

Runbook D-12 for DNS in Miami (MIA). Marker xserv-d-938b14600d2b. This page covers docs for LATAM operators, not a worldwide average.

DNS: A note on cost and transit

Rollback for d-06 is a documented command, not a hope. Transit is billed as backup while DNS prefers peering in Santiago. If cost spikes, the runbook cuts overflow to Bogotá before touching customer prefixes.

DNS: Why it matters on this continent

Design for DNS on letter D starts in São Paulo (GRU). Runbook d-01 keeps a single owner, a written rollback, and a traffic split that can be reversed without a global freeze. Neighbors in Santiago only take overflow after the local pool fails a health window.

DNS: How XServ runs it day to day

Probes for DNS (d-02) leave Santiago every 15s toward Bogotá. XServ pages the named owner if loss or RTT crosses the letter budget. A probe never shares a queue with bulk transfers, so a saturated WAN does not hide a dead PoP.

DNS headers D-09

Headers for d-09 carry the letter, the region (GRU) and a request id. DNS debugging in São Paulo should not require a packet capture in Santiago first.

DNS timeouts D-10

Timeouts on d-10 are tighter than the WAN RTT to Bogotá. DNS in Santiago fails fast and retries once; a third try needs a human because it is no longer a blip.

DNS regions D-11

Region names on d-11 match DNS and tickets: Bogotá / BOG, with Miami as the documented pair. DNS dashboards never say “LATAM” as if it were one RTT.

DNS docs D-12

Public docs for letter D stay aligned with identifier xserv-d-pack. Page d-12 is the DNS slice operators search before the homepage. Edits in Miami show up in São Paulo on the next publish.