Fix the openflow version to 1.3

- The default openflow version of ovs 2.8+ is 1.4
- Add the tips of quagga user

Change-Id: I6e7bd4989df3b63f978f915dfba44938f878bc8a
diff --git a/trellis/trellis_remote_dhcp.py b/trellis/trellis_remote_dhcp.py
index 33a5974..1942dd2 100755
--- a/trellis/trellis_remote_dhcp.py
+++ b/trellis/trellis_remote_dhcp.py
@@ -6,12 +6,13 @@
 from mininet.net import Mininet
 from mininet.cli import CLI
 from mininet.log import setLogLevel
-from mininet.node import RemoteController, OVSBridge, Host
+from mininet.node import RemoteController, OVSBridge, Host, OVSSwitch
 from mininet.nodelib import NAT
 from ipaddress import ip_network
 from routinglib import BgpRouter
 from routinglib import RoutedHost
 from trellislib import DhcpClient, DhcpServer, DhcpRelay
+from functools import partial
 
 class Trellis( Topo ):
     "Trellis basic topology"
@@ -117,7 +118,8 @@
     setLogLevel('debug')
     topo = Trellis()
 
-    net = Mininet(topo=topo, controller=None)
+    switch = partial(OVSSwitch, protocols='OpenFlow13')
+    net = Mininet(topo=topo, controller=None, switch=switch)
     net.addController(RemoteController('c0', ip='192.168.56.11'))
     net.addController(RemoteController('c1', ip='192.168.56.12'))
     net.addController(RemoteController('c2', ip='192.168.56.13'))