Create l2_switching_v3.py

Descriptions:
LLDP is blocked by switches which run 802.1 , since the control logic now resides in the controller , the controller by default considers the switch to be blocking and hence instructs the switch to drop the packet

note to self : merge with existing code

Testing:

mininet@mininet-vm:~$ sudo mn --topo single,3 --mac --switch ovsk --controller remote
*** Creating network
*** Adding controller
*** Adding hosts:
h1 h2 h3 
*** Adding switches:
s1 
*** Adding links:
(h1, s1) (h2, s1) (h3, s1) 
*** Configuring hosts
h1 h2 h3 
*** Starting controller
*** Starting 1 switches
s1 
*** Starting CLI:

mininet> dpctl dump-flows
*** s1 ------------------------------------------------------------------------
mininet>mininet> h1 ping h2
PING 10.0.0.2 (10.0.0.2) 56(84) bytes of data.
64 bytes from 10.0.0.2: icmp_req=1 ttl=64 time=0.230 ms
64 bytes from 10.0.0.2: icmp_req=2 ttl=64 time=0.049 ms
64 bytes from 10.0.0.2: icmp_req=3 ttl=64 time=0.056 ms
64 bytes from 10.0.0.2: icmp_req=4 ttl=64 time=0.050 ms
64 bytes from 10.0.0.2: icmp_req=5 ttl=64 time=0.126 ms
64 bytes from 10.0.0.2: icmp_req=6 ttl=64 time=0.041 ms
64 bytes from 10.0.0.2: icmp_req=7 ttl=64 time=0.129 ms
64 bytes from 10.0.0.2: icmp_req=8 ttl=64 time=0.055 ms
64 bytes from 10.0.0.2: icmp_req=9 ttl=64 time=0.055 ms
^C
--- 10.0.0.2 ping statistics ---
9 packets transmitted, 9 received, 0% packet loss, time 7999ms
rtt min/avg/max/mdev = 0.041/0.087/0.230/0.060 ms
mininet> dpctl dump-flows
*** s1 ------------------------------------------------------------------------
in_port(1),eth(src=00:00:00:00:00:01,dst=00:00:00:00:00:02),eth_type(0x0800),ipv4(src=10.0.0.1,dst=10.0.0.2,proto=1,tos=0,ttl=64,frag=no),icmp(type=8,code=0), packets:8, bytes:784, used:3.872s, actions:3,2,0
in_port(2),eth(src=00:00:00:00:00:02,dst=00:00:00:00:00:01),eth_type(0x0800),ipv4(src=10.0.0.2,dst=10.0.0.1,proto=1,tos=0,ttl=64,frag=no),icmp(type=0,code=0), packets:8, bytes:784, used:3.872s, actions:3,0,1