[ns] help with Implementation of a routing agent with manually configured routing table (Static Routing)

Hello,I have been trying to implement a routing agent with manually
configured routing table (Static Routing) as mentioned in
http://www.winlab.rutgers.edu/~zhibinwu/html/Routing_Agent.html#Agent. I
have created a routing table manually but I am unable to input it to the
the script.I get the following error.Kindly help me with how to input the
routing table file.

Starting Simulation...
FIXRT: configure routing table file open failed!
Segmentation fault

Thank you,
Abinaya