A method performed by a network node, the method comprising: receiving a first message comprising reachability information and data encapsulation capabilities of a first host connected to a first tunnel endpoint in a first network domain, wherein the reachability information and data encapsulation capabilities of the first host are encoded in accordance with a control plane protocol of the first network domain; extracting (82, 84) from the received first message the reachability information and the data encapsulation capabilities of the first host; encoding (82, 84) the extracted reachability information and the data encapsulation capabilities of the first host in accordance with an Application Programming Interface, API, and a database schema of a central controller database of a second network domain; forwarding the encoded reachability information and data encapsulation capabilities of the first host for writing to the central controller database of the second network domain in accordance with the API and the database schema; receiving a second message comprising reachability information and data encapsulation capabilities of a second host connected to a second tunnel endpoint in the second network domain, wherein the reachability information and data encapsulation capabilities of the second host are encoded in accordance with the API and the database schema; extracting from the second message the reachability information and the data encapsulation capabilities of the second host; encoding the extracted reachability information and the data encapsulation capabilities of the second host in accordance with the control plane protocol of the first network domain; and transmitting the second message to the first network domain. receiving a first message comprising reachability information and data encapsulation capabilities of a first host connected to a first tunnel endpoint in a first network domain, wherein the reachability information and data encapsulation capabilities of the first host are encoded in accordance with a control plane protocol of the first network domain; extracting (82, 84) from the received first message the reachability information and the data encapsulation capabilities of the first host; encoding (82, 84) the extracted reachability information and the data encapsulation capabilities of the first host in accordance with an Application Programming Interface, API, and a database schema of a central controller database of a second network domain; forwarding the encoded reachability information and data encapsulation capabilities of the first host for writing to the central controller database of the second network domain in accordance with the API and the database schema; receiving a second message comprising reachability information and data encapsulation capabilities of a second host connected to a second tunnel endpoint in the second network domain, wherein the reachability information and data encapsulation capabilities of the second host are encoded in accordance with the API and the database schema; extracting from the second message the reachability information and the data encapsulation capabilities of the second host; encoding the extracted reachability information and the data encapsulation capabilities of the second host in accordance with the control plane protocol of the first network domain; and transmitting the second message to the first network domain.