code originally tried to do a normal $ns connect between traffic agents
attached to simnodes on the same pnode. The problem that I forgot of course
is that partitioned topology is quite disconnected which means that a
packet is forced to exit the pnode and come back to it (in many cases).
In other words, a direct intra pnode path does not exist. The fix is
to just use the IP address based routes always. A similar problem
is encountered in pdns as well. However, since IP address based routing
is not used, there is no simple fix unless I work on it!

The 416 node topology testbed/nse416 is working alright. It mapped to
20 pnodes and as soon as a whole bunch of traffic started up, 7 pnodes
couldn't track real-time and caused a modify. Expt modify happened 3
times but eventually max_retries in my re-swapping code was reached. Need
more measuring, tuning as well as eventrate based re-swapping.