Ben and Jesse, Thanks for picking this issue up.
Although current behavior is not consistent in VLAN and no-VLAN cases, as far as NetFlow concerns it doesn’t matter in fact because NetFlow only counts L3 packet size anyway. Here’s the story. First, I wanted to fix an issue that OVS currently reports L2 packet size, not L3 packet size in NetFlow flow records (NetFlow should report L3 packet size). I thought the easiest way to fix this problem was to subtract the ethernet header length when reporting a NetFlow flow record. Then, I realized that I should also take VLAN header into account if it is present. I checked how NetFlow behaves in VLAN case and no-VLAN case and found out that OVS reports the same packet size in NetFlow regardless to the presence of VLAN header. Once this packet size issue related to VLAN header gets solved by someone else (as this is probably beyond of my understanding of the relevant code), I will work on fixing the L2 vs L3 packet size issue specifically in NetFlow. Regards, On 2014/12/09 3:22, "Jesse Gross" <je...@nicira.com <mailto:je...@nicira.com>> wrote: On Mon, Dec 8, 2014 at 9:58 AM, Ben Pfaff <b...@nicira.com <mailto:b...@nicira.com>> wrote: Motonori Shindo (CCed) reported to me recently that NetFlow does not include VLAN headers in the byte counts that it exports. Taking a look at the kernel datapath code, I see that ovs_flow_stats_update() accounts raw skb->len to byte counters. I suspect that it should add 4 if a VLAN header was present but removed by VLAN acceleration. Presumably we should also do this for port stats as well to be consistent. --- Motonori Shindo _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
