Bind 8.4.4

[Marcos Rene]

Hello.

I´m working with bind 8.4.4 to resolve my internal network when my 
DNS(ISP) does fail, how can i guarantee that my DNS internal does 
resolve machines local,
if the hosts file of my DNS have other domain name, that doesn´t be the 
name domain given for my ISP?
and other cuestion:
if my DNS local fails, is necessary upgrade it domain name in the DNS of 
my ISP? to resolve with it?
(My DNS local have a domain name different to domain give it for my DNS 
of my ISP, is necessary an alias on the ISP DNS?

What meaning the file .CPR in the /usr directory as apparently my DNS 
does fail and its generate this file?

Greetings . Marcos