[ns] creating routing agent

[siva rupesh ss]

hi ns-users,
                I am trying to implement modified DVMRP . But I am now stuck
at very basic problem. I did not get reply for my
previous post. I am giving link for reference  which is based on my
problem..

http://mailman.isi.edu/pipermail/ns-users/2008-April/062819.html

I figured out that using DDD(Data Display Debugger) that my error
Segmentation fault is due to the routing agent address
   in ph->pkt_src_ =ra_addr() ;  // Here I can't access to memory location..

    I tried by adding MyAgent to ns-lib.tcl and ns-agent.tcl but all in
vain.....

Can anybody help me how to solve this problem. How can I get routing agent
address to be assigned to a variable.
Should I define my agent in tcl file?? I looked in to ns-documentation but
there is no information on how to define my own agent
and how to modify ns-lib.tcl and ns-agent.tcl (
http://www.isi.edu/nsnam/ns/doc/node108.html)

This link gives info on MANET wireless. but even then I followed to modify
ns-lib.tcl ,but got the same error... Can we follow this
even for wired networks ?? or is there any difference in creating own agent
for wired nodes??

http://masimum.dif.um.es/nsrt-howto/html/node20.html
If any one knows how to solve it please respond?? so that your post may be
helpful to many  others like me...

Thank You
Rupesh