More specific topo example filename

custom/topo_2sw_2host.py

@@ -0,0 +1,45 @@
+"""Custom topology example
+
+author: Brandon Heller (brandonh@stanford.edu)
+
+Two directly connected switches plus a host for each switch:
+
+   host --- switch --- switch --- host
+
+Adding the 'topos' dict with a key/value pair to generate our newly defined
+topology enables one to pass in '--topo=mytopo' from the command line.
+"""
+
+from mininet.topo import Topo, Node
+
+class MyTopo( Topo ):
+    """Simple topology example."""
+
+    def __init__( self, enable_all = True ):
+        """Create custom topo."""
+
+        # Add default members to class.
+        super( MyTopo, self ).__init__()
+
+        # Set Node IDs for hosts and switches
+        leftHost = 1
+        leftSwitch = 2
+        rightSwitch = 3
+        rightHost = 4
+
+        # Add nodes
+        self._add_node( leftSwitch, Node( is_switch=True ) )
+        self._add_node( rightSwitch, Node( is_switch=True ) )
+        self._add_node( leftHost, Node( is_switch=False ) )
+        self._add_node( rightHost, Node( is_switch=False ) )
+
+        # Add edges
+        self._add_edge( leftHost, leftSwitch )
+        self._add_edge( leftSwitch, rightSwitch )
+        self._add_edge( rightSwitch, rightHost )
+
+        # Consider all switches and hosts 'on'
+        self.enable_all()
+
+
+topos = { 'mytopo': ( lambda: MyTopo() ) }