Caching name server

[narendar reddy]

I have st up BIND9 as authoritative server for some domains.
Now i want to set up it as cache only name server.
zone "."
 { type hint;
 file "root.servers <root-servers.html>"; };


But instead of above db.cache file, i want to cache from
other BIND9 name server in my LAN only.

Please clarify me How to target my cache server to some other
name server in my LAN itself.

also tell me the command to run BIND9 as a threaded name server.

Thanking You.