Known Issue: The Cache Local DNS Servers global variable can be erroneously disabled when persistence is enabled for a wide IP

(SOL15072) Description The BIG-IP GTM Cache Local DNS Servers global variable (cache-ldns-servers) can be erroneously disabled when persistence is enabled for a wide IP. The Cache Local DNS Servers variable specifies whether or not the BIG-IP GTM system retains all local DNS (LDNS) servers, that make requests, in memory. This setting is enabled by default. This variable must be enabled if you want the system to store and use LDNS persistence information; however, the system allows an administrator to disa