manage.py runserver
Just in case any Windows users are having trouble, I thought I'd add my own experience. When running python manage.py runserver 0.0.0.0:8000, I could view urls using localhost:8000, but not my ip address 192.168.1.3:8000. 
I ended up disabling ipv6 on my wireless adapter, and running ipconfig /renew. After this everything worked as expected.
I am running python manage.py runserver from a machine A
when I am trying to check in machine B.  The url I typed is http://A:8000/ .
I am getting an error like The system returned: (111) Connection refused