Mininet Routing not working

问题:

I have a problem with Mininet topology. I am trying to make a ping between h3 and h4. They are connected to same switch s4. But they can not ping, they are in different subnet, so i am trying to make a flow table for s4 but with no success. Here is image of my topology :

after running Mininet I set up this:

h3 route add default gw 30.0.0.254 h3-eth0
h3 arp -s 30.0.0.254 00:00:00:00:33:33
h4 route add default gw 40.0.0.254 h4-eth0
h4 arp -s 40.0.0.254 00:00:00:00:44:44

Then I populate s4 flow table

table=0,ip,nw_src=30.0.0.3,actions=resubmit(,1)
table=0,ip,nw_src=40.0.0.4,actions=resubmit(,1)
table=0,icmp,nw_src=30.0.0.3,actions=resubmit(,1)
table=0,icmp,nw_src=40.0.0.4,actions=resubmit(,1)

table=1,ip,nw_dst=30.0.0.3,actions=mod_dl_dst=00:00:00:00:00:03,output:1
table=1,ip,nw_dst=40.0.0.4,actions=mod_dl_dst=00:00:00:00:00:04,output:2

table=1,priority=0,arp,nw_dst=30.0.0.3,actions=output:1
table=1,priority=0,arp,nw_dst=40.0.0.4,actions=output:2

when I run ping between h3 and h4 and display s4 dump-flow I am getting this

 table=0, n_packets=1, n_bytes=98, idle_age=6, ip,nw_src=30.0.0.3 actions=resubmit(,1)
 table=0, n_packets=0, n_bytes=0, idle_age=17, ip,nw_src=40.0.0.4 actions=resubmit(,1)
 table=0, n_packets=0, n_bytes=0, idle_age=17, icmp,nw_src=30.0.0.3 actions=resubmit(,1)
 table=0, n_packets=0, n_bytes=0, idle_age=17, icmp,nw_src=40.0.0.4 actions=resubmit(,1)
 table=1, n_packets=0, n_bytes=0, idle_age=17, ip,nw_dst=30.0.0.3 actions=mod_dl_dst:00:00:00:00:00:03,output:1
 table=1, n_packets=1, n_bytes=98, idle_age=6, ip,nw_dst=40.0.0.4 actions=mod_dl_dst:00:00:00:00:00:04,output:2
 table=1, n_packets=0, n_bytes=0, idle_age=17, priority=0,arp,arp_tpa=30.0.0.3 actions=output:1
 table=1, n_packets=0, n_bytes=0, idle_age=17, priority=0,arp,arp_tpa=40.0.0.4 actions=output:2

and Mininet is saying only this:

mininet> h3 ping h4 -c1
PING 40.0.0.4 (40.0.0.4) 56(84) bytes of data.
^C
--- 40.0.0.4 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms

Could you help me please how to make connectivity? Or what is wrong in flow table on s4? Thank you in advance.

回答1:

Install Wireshark and use the command s4 Wireshark to observe the packets between the switch and the hosts. Check if the destination mac address of the packet has properly changed.