ndnSIM

I installed and used ndnSIM 1.0.

When I used the command: git clone -b master-v1 git://github.com:named-data/ndnSIM.git ns-3/src/ndnSIM. I obtain the Error:
fatal: unable to connect to github.com:
github.com: Servname not supported for ai_socktype

I tried the command: git clone git://github.com/NDN-Routing/ndnSIM.git ns-3/src/ndnSIM which I used one year ago, it worked.
But when I compiling and running ndnSIM, I obtain ImportError: No module named doxygen.

Finally, I found the right should be: git clone -b master-v1 git://github.com:named-data/ndnSIM.git ns-3/src/ndnSIM