Landesk vulnerability definitions are hosted on three servers located in US east coast, US west coast and EMEA. Landesk does not host the content of patches anymore. The patch content is downloaded from patch vendor, such as Microsoft, Adobe.
So you may not setup your own 'internal patch definition server'. If the server is in internal network and cannot access Landesk patch definition servers, AKA 'dark core', you may check below two documents: