DNS listeners, DNS Express & BIND

Thanks, I must have been half asleep when I wrote that last comment. I see the DNS express stats increment when the wip is resolved, as well as the wide ip stats. I'm not sure if the latter is anything to go by.

The odd thing is that regardless of the timeouts, the wip always resolves to the correct address, even when I change the priority of the pools, so gslb is working. This is what makes me think it's not lb related.

I basically have 2 listeners, one internal, one external. Internally dns express disabled and bind enabled. Externally dns express enabled and bind disabled.

Internally resolves immediately and externally times out but resolves on the 3rd/4th attempt.

Config is below:

gtm datacenter /Common/DC_1 { }
gtm datacenter /Common/DC_2 { }
gtm prober-pool /Common/DC_1_prober {
    load-balancing-mode round-robin
    members {
        /Common/f51.sample.com {
            order 0
        }
    }
}
gtm region /Common/rfc1918 {
    region-members {
        subnet 10.0.0.0/8 { }
        subnet 172.16.0.0/12 { }
        subnet 192.168.0.0/16 { }
    }
}
gtm server /Common/f51.sample.com {
    datacenter /Common/DC_1
    devices {
        f51.sample.com {
            addresses {
                192.168.157.254 { }
            }
        }
    }
    monitor /Common/bigip_5s
    product bigip
    virtual-servers {
        APP_1 {
            destination 1.1.1.10:443
            translation-address 192.168.157.10
            translation-port 443
        }
        APP_1_int {
            destination 192.168.157.10:443
        }
        APP_2 {
            destination 1.1.1.11:443
            translation-address 192.168.157.11
            translation-port 443
        }
        APP_2_int {
            destination 192.168.157.11:443
        }
    }
}
gtm topology ldns: region /Common/rfc1918 server: subnet 192.168.157.0/24 {
    order 1
}
gtm topology ldns: not region /Common/rfc1918 server: not subnet 192.168.157.0/24 {
    order 2
}
gtm global-settings metrics {
    metrics-collection-protocols { icmp }
}
gtm global-settings metrics-exclusions {
    addresses none
}
gtm monitor bigip /Common/bigip_5s {
    aggregate-dynamic-ratios none
    defaults-from /Common/bigip
    destination *:*
    interval 5
    timeout 15
}
gtm pool a /Common/APP_1_gslbpool {
    alternate-mode none
    fallback-mode none
    load-balancing-mode topology
    members {
        /Common/f51.sample.com:APP_1_int {
            member-order 1
        }
    }
}