Just to get dates in order:

Jun/2014 - deliveries to master branch that introduce IGMP fields to flow 
structure
Sep/2014 - we update from tip of master
Apr/2014 - I notice this potential issue

I am running a simple ryu application (using code from 
https://github.com/samrussell/nss) and connecting my desktop PC to our main 
LAN. Flows with multicast addresses appear to come and go, but I suspect it's 
IGMPv3 Membership Reports (type 0x22) that are causing flows to be created that 
then persist.

In this application at least, matching is done purely on source and destination 
MAC, so the existence of these flows is probably not that much of a problem 
since the flows will cover many other packets that aren't Membership reports. 
It's not really that surprising that this might not be noticed since the switch 
is behaving perfectly normally and acceptably.

To your point of reproducing on unmodified OpenVSwitch, yes, I will do that, 
and report further. Time zones and public holidays mean that it won't be until 
next week.

Tony
________________________________________
From: Ben Pfaff <[email protected]>
Sent: Friday, 24 April 2015 11:08 a.m.
To: Tony van der Peet
Cc: [email protected]
Subject: Re: [ovs-discuss] IGMP fields added to the flow structure causes 
problem?

On Thu, Apr 23, 2015 at 12:03:08AM +0000, Tony van der Peet wrote:
> I have been investigating some anomalous behaviour in a switch
> (developed by us, based on OpenVSwitch code). It appears that flows
> added as a result of receiving IGMP packets are never deleted. Here's
> one of the flows (this is a switch running a simple MAC learning
> application, so you don't see the upper level fields).
>
> recirc_id(0),in_port(2),eth(src=38:60:77:8b:d9:0a,dst=01:00:5e:00:00:16),eth_type(0x0800),ipv4(frag=no),
>  packets:26, bytes:2236, used:9.600s, actions:1,6,5,4,3
>
> Here's a log message I'm seeing:
>
> 2015 Apr 23 12:33:23 awplus ovs-vswitchd: 
> 02570|dpif(revalidator4)|WARN|system@ovs-system: failed to flow_del (No such 
> file or directory)
>  
> skb_priority(0),skb_mark(0),recirc_id(0),dp_hash(0),in_port(2),eth(src=38:60:77:8b:d9:0a,dst=01:00:5e:00:00:16),eth_type(0x0800),ipv4(src=10.33.22.24,dst=224.0.0.22,proto=2,tos=0xc0,ttl=1,frag=no)

Thanks for the report.  I'm a little surprised to hear about this, since
that code is somewhat old (I think you said September 2014) and I don't
remember getting similar reports before.  Can you explain how to
reproduce the problem (with unmodified OVS)?
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