Forum Discussion
Edouard
Cirrus
CirrusF5 DNS and two Service Providers
Greetings,
I have two SP, each one has its own public IP segment.
F5 DNS is setup with Global Availability so member1 linked to SP1 is always active and member2 linked to SP2 is standby.
If SP1 is down, the member1 will be up so the Global Availability will not fail over to the member2.
How do I setup the F5 DNS so it can failover pool members depending on SP availability.
Regards,
Edouard.
JGCumulonimbus
Will you please explain how "If SP1 is down, the member1 will be up so the Global Availability will not fail over to the member2" works?
- Edouard
Yes, because what we are polling is the SP router's gateway which is most of the cases will be active, but the SP network will have an outage. This is because the pool that I have defined as a default gateway is just monitoring the SP default gateway by ICMP. So the links defined in the F5 DNS module ask the LTM module for the status of the default GW only via ICMP.
So if one of the default gateways in the GW pool is marked down by the LTM, the DNS link will be marked down. On the DNS module side, any wide-ip pool members on that link will be marked down, hence the failover happens.
- Edouard
In order to address this inconvenient, that we monitor only the SP GW, we should consider the following KB https://support.f5.com/csp/article/K6848 which states that a transparent monitor should be used to test through the assigned device to a distant point.
