DNS (GTM) best practice for DR
Hi, I need to set DR based on DNS module. After reading few posts and docs all I know that there is plenty approaches that can be implemented. I have little experience with DNS module so I will appreciate any advice what will be optimum solution. Scenario: Two Data Centers: DC1 (main), DR1 (used only when resources in DC not available) Each DC uses non overlapping subnet ranges DCs connected via internal private L2/L3 link All DNS queries will only come from devices inside DCs In each Data Center single BIG-IP DNS device In each DC one host (let's call it Main) requiring DNS resolution for resources it has to access In each DS eight hosts (let's call them Slaves) with separate IP and FQDN - those are not LTMs but standard servers - Generic Host type (monitoring via HTTP monitor) DNS device should perform DNS resolution for FQDNs for Main host DR rules: If any Slave in DC1 is down, DNS request should be resolved to IP of any working Slave If all Slaves in DC1 are down, DNS request should be resolved to IP of any Slave in DR1 What would be best approach? As far as I understand Global Availability method should be used, but at what level: Pool Wide IP Is that better to create on Pool with members from both DSs or separate Pool - one per DC - each containing members from respective DC? Now how to handle condition to return IP of active Slave inside one DC? I guess I need to create as many WideIPs as Slaves (8), or rather one wildcard IP: slave1.vip.site.com, slave2.vip.site.com,...,slave8.vip.site.com or .vip.site.com Then how to perform returning IP of another active Slave when Slave for which DNS request was made is down - inside DC HA? Piotr