feature #4043: Support TTL for VXLAN driver

src/vnm_mad/remotes/OpenNebulaNetwork.conf

@@ -34,3 +34,5 @@
 
 # Base multicast address for each VLAN. The mc address is :vxlan_mc + :vlan_id
 :vxlan_mc: 239.0.0.0
+# Time To Live (TTL) should be > 1 in routed multicast networks (IGMP)
+:vxlan_ttl: 16

src/vnm_mad/remotes/vxlan/vxlan_driver.rb

@@ -45,9 +45,10 @@ class VXLANDriver < VNMMAD::VLANDriver
         mc  = VNMMAD::VNMNetwork::IPv4.to_i(CONF[:vxlan_mc]) + @nic[:vlan_id].to_i
         mcs = VNMMAD::VNMNetwork::IPv4.to_s(mc)
         mtu = @nic[:mtu] ? "mtu #{@nic[:mtu]}" : ""
+        ttl = CONF[:vxlan_ttl] ? "ttl #{CONF[:vxlan_ttl]}" : ""
 
         OpenNebula.exec_and_log("#{command(:ip)} link add #{@nic[:vlan_dev]}"\
-            " #{mtu} type vxlan id #{@nic[:vlan_id]} group #{mcs}"\
+            " #{mtu} type vxlan id #{@nic[:vlan_id]} group #{mcs} #{ttl}"\
             " dev #{@nic[:phydev]}")
 
         OpenNebula.exec_and_log("#{command(:ip)} link set #{@nic[:vlan_dev]} up")