I currently have a SBS 2003 server with DNS serving our internal domain and forwarding unknown domain requests to our ISP's servers. This is OK until our ISP's servers go down or have problems (yes, it has happened!). What I would like to do is implement caching on our server so that even if our ISP's DNS servers go down, we can at least have some DNS functionality (albeit out of date until the ISP DNS server comes back online)
How do I go about doing this? What are the risks?