[mpls-linux-general] about LDP_LINUX port with out MPLS_linux

[<zjh...@so...>]

hi,all
  I have installed LDP_PORTABLE on my pc.I have succeed on compiling the program.But
 when I run it between two PCs,the program on each PC can send the UDP HELLO message.
 But the message can't be received and so there is no session established!
What is the reason?
  I have tried to modified the TCP/UDP port used by LDP from 646 to 8000.then the session 
 have been established and everything is OK! 
I want to know can i make the program run OK under Linux with out MPLS_LINUX using th port 646?
Must I modified the *.conf in /etc/...? If so ,How?
 all thanks!!
 jianhui zhang