last refresh, wait the retry value before trying again. This value isn't as important as others, unless the secondary is on a distant network from the primary or the primary is more prone to outages. It's typically some fraction of the refresh interval."
data as valid if it can't contact the primary. This value should be greater than how long a major outage would typically last, and must be greater than the minimum and retry intervals"
Backbone Networks "https://hal.inria.fr/inria-00000888/file/D3.6.1.pdf" página 50 indica: "retry should be smaller than refresh"
- Guia: "Check Point™ Meta IP User’s Guide" pagina 114 indica: "Slave Refresh must be lower than Slave Data Expire and Zone Default TTL"
- Sobre el serial no debería ser 0: https://mxtoolbox.com/problem/dns/dns-soa-serial-number-format y https://www.digitalocean.com/community/questions/soa-serial-number-format-is-invalid (sin embargo algunos software de DNS lo aceptan)