Setup manual

Service addresses

Each nameserver below is an independent secondary with its own transfer address — allow AXFR/IXFR from both, not just one.

Setup

1. Add the zone in the panel. Give your primary's address, or leave it blank and we'll take it from your zone's SOA MNAME. If your primary answers transfers on a non-standard port, put it in the port field; blank means 53.
2. Allow AXFR/IXFR from 149.56.45.244 and 51.91.251.100 on your primary — both addresses, not just one.
3. Add ns1.otterdns.net and ns2.otterdns.net to the zone apex NS set and the registrar delegation. At least one is required; we recommend delegating both for full redundancy.
4. Optional: configure NOTIFY to both transfer addresses so updates propagate in seconds.

No TSIG: our published source addresses authorize the transfer.

Configuration examples

BIND (named.conf)

zone "example.com" {
    type primary;
    file "example.com.zone";
    allow-transfer { 149.56.45.244; 51.91.251.100; };
    also-notify { 149.56.45.244; 51.91.251.100; };
};

PowerDNS Authoritative (pdns.conf)

allow-axfr-ips=149.56.45.244/32,51.91.251.100/32

also-notify=149.56.45.244,51.91.251.100

Knot DNS (knot.conf)

remote:
  - id: otterdns-ns1
    address: 149.56.45.244
  - id: otterdns-ns2
    address: 51.91.251.100
acl:
  - id: otterdns-ns1-transfer
    address: 149.56.45.244
    action: transfer
  - id: otterdns-ns2-transfer
    address: 51.91.251.100
    action: transfer
zone:
  - domain: example.com
    acl: [otterdns-ns1-transfer, otterdns-ns2-transfer]
    notify: [otterdns-ns1, otterdns-ns2]

NSD (nsd.conf)

zone:
    name: "example.com"
    zonefile: "example.com.zone"
    provide-xfr: 149.56.45.244 NOKEY
    notify: 149.56.45.244 NOKEY
    provide-xfr: 51.91.251.100 NOKEY
    notify: 51.91.251.100 NOKEY

Delegation

Keep at least one of ns1.otterdns.net / ns2.otterdns.net in your delegation — both is better. A zone that goes 30 days with neither is removed, and the zone's page shows the exact date well before that happens.

We'd also recommend keeping a nameserver that isn't ours in there — your own primary counts. It's not required, but if we're the only nameserver you delegate to, an OtterDNS outage takes your zone with it.