Hi, all. I think I find a bug here. As the question I said last time(dec_ttl).
My network is h1-s2-s3-h2 My setup is mininet2.1+ovs2.0. I used this setup as Justin said. And then I still add a flow whose actions include "dec_ttl" on s2(switch 2). And I still cannot find any differences on h2 when I use "h1 sendip -d dsf -p ipv4 -is 10.0.0.1 -it 10 -id 10.0.0.2 10.0.0.2" command on h1. I used "tcpdump -v" to check the packet's ttl on h2. The ttl is still "10" as I set previously. I'm really upset at that time, and then when I use sendip. I try to set the ttl is 1. Like this command.:h1 sendip -d dsf -p ipv4 -is 10.0.0.1 -it 1 -id 10.0.0.2 10.0.0.2 Finally, I find that I cannot match this packet on s3 and cannot receive the packet on h2. So I think it works. But if I send this:h1 sendip -d dsf -p ipv4 -is 10.0.0.1 -it 2 -id 10.0.0.2 10.0.0.2 I can still receive the packet on h2 and use tcpdump to check ttl, then it still shows "2". After this result, I use a physical network environment to see whether tcpdump works if I change the ttl. And it works. So I think the "ttl" that ovs has changed is not the real ttl. But virtual one. I want to ask how can I detect this on h2 ? ---Allan On Tue, Feb 4, 2014 at 12:52 PM, Justin Pettit <jpet...@nicira.com> wrote: > Does it properly decrement the TTL if you don't modify the TOS? Does it > behave as you'd expect with OVS 2.0 (the latest release)? > > --Justin > > > On Feb 3, 2014, at 7:00 PM, Allan Jie <allanmcgr...@gmail.com> wrote: > > I want to clarify the problem. And I don't why I cannot post that > correctly. > > Now here is the thing. > I start a network like 4 host and 1 switches. > h1,h2 and s1. > > I know the dec_ttl action is for ipv4 packet and openflow 1.1+. > > So I have finished this command. > ovs-vsctl set bridge s1 protocols=OpenFlow10,OpenFlow12,OpenFlow13 > And also use -O OpenFlow13 in ovs-ofctl. > Like the following line: > ovs-ofctl -O OpenFlow13 add-flow s1 > table=0,priority=65535,ip,in_port=1,vlan_tci=0x0000,dl_src=9e:60:7c:45:f2:b8,dl_dst=32:a2:19:d3:56:4f,nw_src=10.0.0.1,nw_dst=10.0.0.2,nw_proto=0,nw_tos=0,actions=output:2,dec_ttl > > Then in h1, I use the command > h1 sendip -d dsf -p ipv4 -is 10.0.0.1 -id 10.0.0.2 10.0.0.2 > which will send an "ip packet" from h1 to h2. > > And then in h2, I use this command to listen the port. > tcpdump ip host 10.0.0.1 -v > > But the result is I cannot see any changes of the ttl in the received > packet. The ttl value is still 64. > > > I have done that according to Justin information. But I still cannot get > it work. I change the ovs-ofctl like this as you said. (position of dec_ttl > and output) > ovs-ofctl -O OpenFlow13 add-flow s1 > table=0,priority=65535,ip,in_port=1,dl_src=3e:a4:62:46:92:28,dl_dst=86:9e:4b:4c:54:53,nw_src=10.0.0.1,nw_dst=10.0.0.2,nw_proto=0,nw_tos=0,actions=dec_ttl,output:2 > > However, when I also use another actions, it seems that it doesn't work > too. Like I use this following actions > actions=del_ttl,mod_nw_tos:0x08,output:2 > But I use tcpdump ip host 10.0.0.1 -v > I cannot see any change of the "tos" value of the packet. Here comes the > result of tcpdump > ------------------------------------ > 10.0.0.1 > 10.0.0.2: ip 3 > 17:57:42.921902 IP (tos 0xc0, ttl 64, id 56235, offset 0, flags [none], > proto ICMP (1), length 51) > -------------------------------- > My environment is mininet 2.1 and openvswitch 1.10. > > Maybe I will try to clarify my problem again. > My setup is very simple. Using Mininet to configure this network. > h1 (h1-eth0)----(s1-eth1)s1(s1-eth2)---(h1-eth0)h2. > > I start the network using this command. > sudo mn --switch ovsk --mac --custom ~/mininet/custom/LinkCustom.py --topo > mytopo > BTW, I try to use the following command to modify something. > sudo ovs-ofctl -O OpenFlow13 add-flow s1 > table=0,priority=65535,ip,in_port=1,dl_src=fe:81:d2:69:f6:74,dl_dst=de:dc:30:cd:6f:66,nw_src=10.0.0.1,nw_dst=10.0.0.2,nw_proto=0,nw_tos=0,actions=dec_ttl,mod_nw_dst:10.0.0.3,mod_dl_dst:00:00:00:00:00:11,output:2 > > And it did change the dst ip and dst mac. (I also use tcpdump command to > monitor on the h2 side) > However, dec_ttl still doesn't work. Can anybody help me out? > > > -- > Research student, final-year undergraduate > Extreme Scale Network Computing and service laboratory( > http://www.cloud-uestc.cn/cloud-uestc-EN/index.html), > School of Computer Science & Engineering, > University of Electronic Science and Technology of China( > http://www.oice.uestc.edu.cn/en/). > Website: http://www.allanjie.ml/ > > _______________________________________________ > discuss mailing list > discuss@openvswitch.org > http://openvswitch.org/mailman/listinfo/discuss > > -- Research student, final-year undergraduate Extreme Scale Network Computing and service laboratory( http://www.cloud-uestc.cn/cloud-uestc-EN/index.html), School of Computer Science & Engineering, University of Electronic Science and Technology of China( http://www.oice.uestc.edu.cn/en/). Website: http://www.allanjie.ml/
_______________________________________________ discuss mailing list discuss@openvswitch.org http://openvswitch.org/mailman/listinfo/discuss
