Adding example to gratuitiously ARP from all hosts

examples/arping.py

@@ -0,0 +1,36 @@
+#!/usr/bin/python
+
+"""
+Create a simple, star topology and gratuitiously ARP from each host,
+which may aid in a network controller's host discovery. However, these
+ARPs will not populate the ARP tables of the other hosts.
+
+This can also be done from the Mininet CLI:
+mininet> py [ h.cmd('arping -U -c 1 ' + h.IP()) for h in net.hosts ]
+"""
+
+from mininet.log import setLogLevel
+from mininet.util import quietRun
+from mininet.log import error
+from mininet.cli import CLI
+from mininet.net import Mininet
+from mininet.topo import SingleSwitchTopo
+
+if __name__ == '__main__':
+
+    if not quietRun( 'which arping' ):
+        error( "Cannot find command 'arping'\nThe package",
+               "'iputils-arping' is required in Ubuntu or Debian\n" )
+        exit()
+    
+    setLogLevel( 'info' )
+
+    net = Mininet( topo=SingleSwitchTopo( k=10 ), waitConnected=True )
+    net.start()
+
+    for host in net.hosts:
+        print host
+        print host.cmd( 'arping -U -c 1 ' + host.IP() )
+
+    CLI( net )
+    net.stop()