how to increasing routing table entries

hi ,
I need to routing table entries.How can it be done.
using Script I'm adding entries into routing table.it supports upto 250.but i need to add more than this limit.
is there any way that we can tweak kernel code and increase the limitation??
:confused:

Currently the Linux kernel supports up to 255 routing tables if CONFIG_IP_MULTIPLE_TABLES is defined when building a kernel. However, a kernel only uses two routing tables (local, main) by default when there is no support for Policy Routing.

Do a search for fib_lookup() and it will lead you to lots of information about kernel routing tables.