Routing table update

Hello. I have questions about updated retrieving routing table.

I deleted a route/entry from the routing table using 'route del...' command, and used 'route' to display the routing table. The routing table does not show the deleted entry, but the file /proc/net/route still has the deleted entry.

I would like to read the file /proc/net/route to plot a network topology, but this file doesn't seems to be updated whenever i deleted an entry.

What file i should i access this updated routing table? or what should i do to get the updated table? Any suggestion?
btw, it works fine with adding an entry....

Thank you very much
tan