I am trying to add our F5 GTM as one of our name servers for a global DNS initiative. The IPs have been added as an A record but when I am trying to add to the list of servers to allow zone transfers to I get the following errors... 

"an unknown error occurred while validating" and the second error states "The zone transfer settings cannot be updated. The IP address is invalid." 

DNS is AD Integrated. I am looking for any ideas on how to resolve this.

Hi,

According to your description, my understanding is that AD-Integrated zone cant be transferred to the newly added (non-Microsoft) DNS server, and prompts error.

Note that, the option to store the zone in Active Directory is only available if the DNS server computer is operating as a domain controller. When this zone type is selected for use, zone data is stored and replicated as part of the AD DS database. 

So, only DC can be configured with AD-Integrated zone. And AD-Integrated zone is only transferred between DCs.

Best Regards,
Eve Wang