To test monitoring using mininet

1) Start ripcord-nox with monitoring enabled

a) Start monitoring component with default values
./nox_core -v -i ptcp: routingengine hostmanager="appid=1" 
topodb="topo=fattree4" monitoring pyrouting
b) Start monitoring component with custom values
./nox_core -v -i ptcp: routingenge hostmanager="appid=1" topodb="topo=fattree4" monitoring="table_poll=2,port_poll=3,aggregate_poll=4,epoch_duration=10,max_snapshots=20" pyrouting

2) Run mininet
sudo mn_run.py --controller nox_pysw ping_pair

3) Things to look for:
a) monitoring should display a message indicating that it has started
b) monitoring will display messages about updating its logical clock, which
tracks collection epochs
c) as switches join and leave the network, monitoring will indicate that
switches a specific dpid announced its arrival/departure
d) monitoring will periodically indicate that table, port, and aggregate
statistics were received from the switch
