linuxrouter.py: changing name, printing routing table, and some more documentation

examples/linuxrouter.py

@@ -16,33 +16,37 @@ The topology contains a router with three IP subnets:
  - h2 (IP: 172.16.0.100)
  - h3 (IP: 10.0.0.100)
 
+ Routing entries can be added to the routing tables of the 
+ hosts or router using the "ip route add" or "route add" command.
+ See the man pages for more details.
+
 """
 
 from mininet.topo import Topo
 from mininet.net import Mininet
 from mininet.node import Node
-from mininet.log import setLogLevel
+from mininet.log import setLogLevel, info
 from mininet.cli import CLI
 from mininet.util import irange
 
-class Router( Node ):
+class LinuxRouter( Node ):
     "A Node with IP forwarding enabled."
 
     def config( self, **params ):
-        super( Router, self).config( **params )
+        super( LinuxRouter, self).config( **params )
         # Enable forwarding on the router
         self.cmd( 'sysctl net.ipv4.ip_forward=1' )
 
     def terminate( self ):
         self.cmd( 'sysctl net.ipv4.ip_forward=0' )
-        super( Router, self ).terminate()
+        super( LinuxRouter, self ).terminate()
 
 
 class NetworkTopo( Topo ):
     "A simple topology of a router with three subnets (one host in each)."
 
     def build( self, n=2, h=1, **opts ):
-        router = self.addNode( 'r0', cls=Router, ip='192.168.1.1/24' )
+        router = self.addNode( 'r0', cls=LinuxRouter, ip='192.168.1.1/24' )
         h1 = self.addHost( 'h1', ip='192.168.1.100/24', defaultRoute='via 192.168.1.1' )
         h2 = self.addHost( 'h2', ip='172.16.0.100/12', defaultRoute='via 172.16.0.1' )
         h3 = self.addHost( 'h3', ip='10.0.0.100/8', defaultRoute='via 10.0.0.1' )
@@ -54,6 +58,8 @@ def run():
     topo = NetworkTopo()
     net = Mininet( topo=topo, controller=None ) # no controller needed
     net.start()
+    info( '*** Routing Table on Router\n' )
+    print net[ 'r0' ].cmd( 'route' )
     CLI( net )
     net.stop()