I took a look at my 865L and theres only 4 Presets for the Servers, You have to pick 1 of those 4 services, depending on which service you signed up for. One you selected 1 of the 4 services, then you enter in the additional Host Name and User account information...I presume since there is only 4 presets listed, that using any other DNS services are not allowed on this router.