1.浏览RYU官网学习RYU控制器的安装和RYU开发入门教程，提交你对于教程代码的理解，包括但不限于：
描述官方教程实现了一个什么样的交换机功能?
functionality that sends a received packet to all the ports将接收到的数据包发送到所有端口的功能
控制器设定交换机支持什么版本的OpenFlow？
OFP_VERSIONS = [ofproto_v1_0.OFP_VERSION]设定交换机支持OpenFlow1.0
控制器设定了交换机如何处理数据包？
actions = [ofp_parser.OFPActionOutput(ofp.OFPP_FLOOD)] 将接收到的数据包发送到所有端口
2.根据官方教程和提供的示例代码（SimpleSwitch.py），将具有自学习功能的交换机代码（SelfLearning.py）补充完整
# TODO define OpenFlow 1.0 version for the switch
OFP_VERSIONS = [ofproto_v1_0.OFP_VERSION]
# TODO send modified message out
datapath.send_msg(mod)
# TODO define the action for output
actions = [datapath.ofproto_parser.OFPActionOutput(out_port)]
# TODO define the OpenFlow Packet Out
out = datapath.ofproto_parser.OFPPacketOut(
datapath=datapath,
buffer_id=msg.buffer_id,
in_port=msg.in_port,
actions=actions, data=data)
datapath.send_msg(out)
全部具有自学习功能的交换机代码（SelfLearning.py）如下
from ryu.base import app_manager
from ryu.controller import ofp_event
from ryu.controller.handler import MAIN_DISPATCHER
from ryu.controller.handler import set_ev_cls
from ryu.ofproto import ofproto_v1_0
from ryu.lib.mac import haddr_to_bin
from ryu.lib.packet import packet
from ryu.lib.packet import ethernet
from ryu.lib.packet import ether_types
class SimpleSwitch(app_manager.RyuApp):
# TODO define OpenFlow 1.0 version for the switch
OFP_VERSIONS = [ofproto_v1_0.OFP_VERSION]
def __init__(self, *args, **kwargs):
super(SimpleSwitch, self).__init__(*args, **kwargs)
self.mac_to_port = {}
def add_flow(self, datapath, in_port, dst, src, actions):
ofproto = datapath.ofproto
match = datapath.ofproto_parser.OFPMatch(
in_port=in_port,
dl_dst=haddr_to_bin(dst), dl_src=haddr_to_bin(src))
mod = datapath.ofproto_parser.OFPFlowMod(
datapath=datapath, match=match, cookie=0,
command=ofproto.OFPFC_ADD, idle_timeout=0, hard_timeout=0,
priority=ofproto.OFP_DEFAULT_PRIORITY,
flags=ofproto.OFPFF_SEND_FLOW_REM, actions=actions)
# TODO send modified message out
datapath.send_msg(mod)
@set_ev_cls(ofp_event.EventOFPPacketIn, MAIN_DISPATCHER)
def _packet_in_handler(self, ev):
msg = ev.msg
datapath = msg.datapath
ofproto = datapath.ofproto
pkt = packet.Packet(msg.data)
eth = pkt.get_protocol(ethernet.ethernet)
if eth.ethertype == ether_types.ETH_TYPE_LLDP:
# ignore lldp packet
return
if eth.ethertype == ether_types.ETH_TYPE_IPV6:
# ignore ipv6 packet
return
dst = eth.dst
src = eth.src
dpid = datapath.id
self.mac_to_port.setdefault(dpid, {})
self.logger.info("packet in DPID:%s MAC_SRC:%s MAC_DST:%s IN_PORT:%s", dpid, src, dst, msg.in_port)
# learn a mac address to avoid FLOOD next time.
self.mac_to_port[dpid][src] = msg.in_port
if dst in self.mac_to_port[dpid]:
out_port = self.mac_to_port[dpid][dst]
else:
out_port = ofproto.OFPP_FLOOD
# TODO define the action for output
actions = [datapath.ofproto_parser.OFPActionOutput(out_port)]
# install a flow to avoid packet_in next time
if out_port != ofproto.OFPP_FLOOD:
self.logger.info("add flow s:DPID:%s Match:[ MAC_SRC:%s MAC_DST:%s IN_PORT:%s ], Action:[OUT_PUT:%s] ",
dpid, src, dst, msg.in_port, out_port)
self.add_flow(datapath, msg.in_port, dst, src, actions)
data = None
if msg.buffer_id == ofproto.OFP_NO_BUFFER:
data = msg.data
# TODO define the OpenFlow Packet Out
out = datapath.ofproto_parser.OFPPacketOut(datapath=datapath, buffer_id=msg.buffer_id, in_port=msg.in_port,
actions=actions, data=data)
datapath.send_msg(out)
print("PACKET_OUT...")
3.在mininet创建一个最简拓扑，并连接RYU控制器
- 用
sudo mn --controller=remote,ip=127.0.0.1,port=6633创建只有一个交换机两个主机的简单Topo
4.验证自学习交换机的功能，提交分析过程和验证结果
在链接Ryu控制器前
- 利用命令
h1 ping h2可以在wireshark上看到 交换机端口s1-eh1是有收到ARP请求但是端口s1-eh2没有任何检测到任何包，这是因为初始时交换机s1的路由表为空且对收到的包不做任何处理
链接Ryu控制器后
- 再次利用命令
h1 ping h2就可以在wireshark上检测到端口s1-eh2收到了ARP请求 ，这是因为Ryu控制器中设置将交换机收到的包进行广播
5.写下你的实验体会
- 装Ryu控制器是真的麻烦
- python空格非法是真的坑
