def policy(self):
policies = []
for switch in self.nib.switches_present():
dpid = self.nib.switch_to_dpid(switch)
# In normal mode, we capture ARP requests for IP's that don't really exist. You can
# think of them as symbolic links to the real IP. We capture .1 address of
# each of the endpoint networks, plus any real hosts on the net
# And we capture ARP requests for the alternate paths. These will always be for
# hosts that have no real estate on the imaginary link, as in 192.168.156.100 along
# the 192.168.156.* imaginary network. This will be translated to the real net 192.168.56.100
# Note: only the routers actually send these requests, not end hosts, who always send them
# to a default gateway.
for ap in self.nib.alternate_paths():
(net, mask) = NetUtils.net_mask(ap[switch])
policies.append(Filter(Policies.at_switch(dpid) & Policies.is_arp() & IP4DstEq(net,mask)) >> Policies.send_to_controller())
return Union(policies)
def router_learning_policy(self): # In the intial config, grab all ARP replies for ourselves return Filter( Policies.is_arp() ) >> Policies.send_to_controller()
