[Koha] Koha Networking issues

[Ken K]

Hello, I'm a librarian in a public library and we recently installed koha
in the library server via a virtual machine using Oracle Virtual-Box and
assigned it a pubic IP, to enable worldwide access of the opac. However,
there has been a lot of Internet fluctuations in the library which has been
inconveniencing the circulation of books making the library staffs to make
use of offline circulation in the busy library. I was asking whether there
is a way to enable private IP inside the organization local network to be
used as a fallback network when the Internet is lost.
Kindly assist