Comments on: Port mirroring with Linux bridges

By: Hayati

Hayati — Mon, 13 Mar 2017 17:59:10 +0000

Great article,

Thanks for your time and sharing!

By: waldner

waldner — Fri, 20 Mar 2015 14:44:40 +0000

In reply to ash. As usual, too little information and too confused. Other than carefully reviewing all the configurations (on the host and the VM) and restarting services/VM if possible, I have no suggestions.

By: ash

ash — Fri, 20 Mar 2015 11:28:38 +0000

In reply to waldner. Thanks for your help.Now the stats are increasing for mirroring but i am not able to see the packets on the vm.Could you please tell me the configuration for that. What i am doing is i am assigning the port of vm as the output port of the mirror.The packets are there on teh interface , but on thr vm attached to it , i am not able to see the packets.

By: waldner

waldner — Sat, 07 Mar 2015 11:11:48 +0000

In reply to ash. Firt of all, I'd check traffic with tcpdump rather than merely with stats. Second, you don't show the bridge configuration, only the mirror. If you do a ovs-vsctl list bridge br0 you should see that the mirror is attached to the bridge, that is, you should see a line like mirrors : [47168566-d187-4638-9451-b6489d74b3ec] where 47168566-d187-4638-9451-b6489d74b3ec is the UUID of the mirror "mymirror". If that doesn't work either, I'm out of ideas.

By: ash

ash — Tue, 03 Mar 2015 10:22:59 +0000

Thanks for your reply.I am using the following configuration:

# ./ovs-vsctl show
2ff82647-0f4b-42de-808b-13921ce67bf8
Bridge "br0"
Port "vm3"
Interface "vm3"
Port "vm2"
Interface "vm2"
type: fpa
Port "br0"
Interface "br0"
type: internal
Port "vm1"
Interface "vm1"
type: fpa

I am trying to mirror traffic port vm1 to port vm3.

used the following command to set the src and dst port:

./ovs-vsctl get port vm1 _uuid
c30998c7-6362-45e3-9154-ff47d1fe6874
./ovs-vsctl set mirror mymirror select_src_port=c30998c7-6362-45e3-9154-ff47d1fe6874 select_dst_port=c30998c7-6362-45e3-9154-ff47d1fe6874

./ovs-vsctl -- --id=@vm3 get port vm3 -- set mirror mymirror output-port=@vm3

but when i run the traffic , i ma not getting any stats increase.

-bash-4.2# ./ovs-vsctl list mirror mymirror
_uuid : 47168566-d187-4638-9451-b6489d74b3ec
external_ids : {}
name : mymirror
output_port : 76e0e296-08d1-4723-ad7e-f730df4edd5b
output_vlan : []
select_all : false
select_dst_port : [c30998c7-6362-45e3-9154-ff47d1fe6874]
select_src_port : [c30998c7-6362-45e3-9154-ff47d1fe6874]
select_vlan : []
statistics : {}

Could you please tell me what i ma doing wrong here.