Hi, Could u please clarify whether removing some flow entries using flow_mod in a switch, will result in packet loss when we are not deleting the flow entries that are used currently to send the traffic?
Further if we have some low priority entries(wildcard) and some high priority entries for the same match conditions are added(exact match), then will we have both the entries. According to my understanding, ow the packets that match the exact match entry will follow the high priority entries and as a result low priority entries will get deleted after some time.Is my understanding correct? Thanks and Regards, Padma V On Sat, Nov 15, 2014 at 6:07 PM, Murphy McCauley <murphy.mccau...@gmail.com> wrote: > On Nov 15, 2014, at 4:29 AM, Padma Jayasankar <padmaj...@gmail.com> wrote: > > Hi, > Thanks for the immediate response. > Regarding > 1) Yes .am using l2_multi with openflow_discovery packets.. So *is > this to forwrd LLDP packets of other switches to the controller?* > > > Yes. This is how discovery works. > > 2) Is this the correct way of deleting? Actually now i have the entries > with other ports in the flow table. So it is deleting the entries with the > specified conditions i guess. But i am getting packet loss which are using > these existing entries(the entries which are present in the table) > To be clear,i have to entries with different priorities for the same > destination in the switch. I give ping request thru xterm and > give "link s3 s7 down". I have modified OVSK, so when a link fails it > deletes the flow entries which has outport as the specified one. *But > inport match case fails..that entry is still present in the table.* > 3) when v senf ofp_flow_mod with OFP_DELETE for some entry and at that > time the packets r flowing thru that switch(thru another link), then will > that flow get affected? Actually some packets are getting dropped while > this flow_mod message is sent. any reason? > > > I can't attempt to reason about what a modified version of OVS might do. > Sorry. > > > On Sat, Nov 15, 2014 at 8:53 AM, Murphy McCauley < > murphy.mccau...@gmail.com> wrote: > >> On Nov 14, 2014, at 7:12 PM, Padma Jayasankar <padmaj...@gmail.com> >> wrote: >> >> HI, >> 1. I am getting the following entry in all switches. What does this >> entry denote? >> *cookie=0x0, duration=100.653s, table=0, n_packets=34, n_bytes=1394, >> idle_age=1, priority=65000,dl_dst=01:23:20:00:00:01,dl_type=0x88cc >> actions=CONTROLLER:65535* >> >> >> I'm guessing this is the output from ovs-ofctl or dpctl or something. >> It's probably worth learning to use the tool; it probably has a man page. >> It should also be pretty clear if you take a look at the OpenFlow spec. >> >> The high points of this entry are that packets with the destination MAC >> 01:23:20:00:00:01 and Ethertype 0x88cc are sent to the controller. 0x88cc >> is LLDP. And if you look up the OUI of the MAC address, you'll see that >> it's Nicira Networks. This is the multicast MAC address used for >> Nicira-style discovery. You're probably running the POX discovery >> component, which installs table entries like this. >> >> 2. I am using POX with Mininet and OVSK. I am using l2_multi >> routine.This deletes all the flow entries when a link failure(link down) >> event is raised. I want to change this , so that it deletes entries >> pertaining the failed link alone.How to achieve this? I tried with the >> following code >> ie) *How to delete entries of a switch that has outport or inport as >> the specified port numbe*r >> >> * clear = of.ofp_flow_mod(command=of.* >> *OFPFC_DELETE,out_port=port1)* >> * sw1.connection.send(clear)* >> >> *clear = of.ofp_flow_mod(command=of.* >> *OFPFC_DELETE,match=of.ofp_**match(in_port=port2)) * >> * sw2.connection.send(clear)* >> >> But it is not behaving as expected >> >> >> What's it doing instead? >> >> Please clarify. >> >> Thanks and Regards, >> Padma V >> >> >> > >
