F5 fallback pool
Assume the below config. If all the members of dns-53-A are down how does the virtual server behave? Given that there is an irule to LB members to a different pool will the VS remain up even though his default pool is currently down? I understand that a VS's status will reflect the underlying pool but does it know to check pools you may have listed in your attached irule?
rule DNS_POOL_FALLBACK {
when CLIENT_ACCEPTED {
if { [active_members "dns-53-A"] < 1 } {
pool "dns-53-B"
}
}
}
pool dns-53-A {
monitor all dns_monitor and dns_monitor_tcp
members {
10.0.0.14:domain {}
10.0.0.15:domain {}
}
}
pool dns-53-B {
monitor all dns_monitor and dns_monitor_tcp
members {
172.16.0.14:domain {}
172.16.0.15:domain {}
172.16.0.114:domain {}
172.16.0.115:domain {}
}
}
virtual dns-tcp {
snat automap
pool dns-53-A
destination 10.1.0.15:domain
ip protocol tcp
rules DNS_POOL_FALLBACK
}
virtual dns-udp {
snat automap
pool dns-53-A
destination 10.1.0.15:domain
ip protocol udp
rules DNS_POOL_FALLBACK
}