add new bridges in Neutron

asked 2015-07-31 08:08:08 -0600

busyboy gravatar image

in a more simpler way, I have two physical interfaces appearing on my compute1 node and what I'm looking for is to pass a particular VM's traffic through those 2 interfaces.

here are my bridges so far.

compute1:~# brctl show
bridge name     bridge id               STP enabled     interfaces
qbr13782ec7-d1          8000.9e16abcd22fc       no              qvb13782ec7-d1
qbr1f41d70b-11          8000.96044cb334e1       no              qvb1f41d70b-11
qbr3afee3e8-6d          8000.f2344a02b9bd       no              qvb3afee3e8-6d
qbr879faa1b-74          8000.52b029673564       no              qvb879faa1b-74
qbrd613b9fc-47          8000.ae36442da27d       no              qvbd613b9fc-47
qbrd69b1c68-73          8000.c23a3b874851       no              qvbd69b1c68-73
qbrf78675d3-9e          8000.c617f27c312f       no              qvbf78675d3-9e
virbr0          8000.525400b3c24b       yes             virbr0-nic
compute1:~# ovs-vsctl show
    Bridge br-int
        fail_mode: secure
        Port "qvo13782ec7-d1"
            tag: 14
            Interface "qvo13782ec7-d1"
        Port "qvo3afee3e8-6d"
            tag: 15
            Interface "qvo3afee3e8-6d"
        Port "qvo879faa1b-74"
            tag: 14
            Interface "qvo879faa1b-74"
        Port "qvod613b9fc-47"
            tag: 13
            Interface "qvod613b9fc-47"
        Port "qvof78675d3-9e"
            tag: 14
            Interface "qvof78675d3-9e"
        Port br-int
            Interface br-int
                type: internal
        Port "qvod69b1c68-73"
            tag: 13
            Interface "qvod69b1c68-73"
        Port patch-tun
            Interface patch-tun
                type: patch
                options: {peer=patch-int}
    Bridge br-tun
        fail_mode: secure
        Port "gre-0a000115"
            Interface "gre-0a000115"
                type: gre
                options: {df_default="true", in_key=flow, local_ip="", out_key=flow, remote_ip=""}
        Port patch-int
            Interface patch-int
                type: patch
                options: {peer=patch-tun}
        Port br-tun
            Interface br-tun
                type: internal
    ovs_version: "2.3.1"

apparently, this is the bridge that I need to break and then add my external interfaces.

qbr879faa1b-74          8000.52b029673564       no              qvb879faa1b-74

external interfaces are eth4 and eth5. traffic from VM will go to eth4 and then it will return back to OvsBridge from eth5.

Any idea.

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2 answers

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answered 2015-08-01 03:39:07 -0600

dbaxps gravatar image

Network traffic will reach br-int via veth-pair (qvb879faa1b-74, qvo879faa1b-74)
Then it will be forwarded to br-tun and left the compute node through gre tunnel.
GRE endpoint interface should be ( eth4 or eth5)
At least one of this interfaces should support GRE tunnel, another one management network.
Packets coming back from Network Node ( say HTTP response ) to your VM will pass
same GRE tunnel in opposite direction and arrive
via br-tun,patch-tun,patch-int,br-int and mentioned veth-pair to VM initiated for instance HTTP request
Details here :-

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answered 2015-08-03 03:08:33 -0600

busyboy gravatar image

I was expecting this , but as I requested in my OP, I just need to break the "qbr879faa1b-74" bridge and then add ports eth4 and eth5,

Adding a new bridge looks pretty simpler, but I dont have detailed information how these flows are controllerd when we mix linux and OVS bidges. like traffic lands from VM instance to the TAP interface and then after passing through the QBR bridge, it enters the bt-int bridge using the qvo interface.

this looks like this

VM-->eth0 Interface  --> TAP-Interface --> QBR-Interface --> QVB-Bridge --> QVO-Interface --> br-int-Bridge

return path is also same like

VM <--eth0 Interface  <-- TAP-Interface <-- QBR-Interface <-- QVB-Bridge< -- QVO-Interface <-- br-int-Bridge

the only mechanism I'm seeing is that I can break the TAP and QBR interfaces and then add my own physical interface bridge like below

 VM-->eth0 Interface  --> TAP-Interface --> ETH4 --> hard-bridge --> ETH5  --> QBR-Interface --> QVB-Bridge --> QVO-Interface --> br-int-Bridge

You see I need to integrate the external bridge "hard bridge" using eth4 and eth5 ports, this is where I'm stuck like to how to integrate them to TAP and QBR interfaces.


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Just to clear, I just want this to be done for only 1 particular VM. This is the requirement.....

busyboy gravatar imagebusyboy ( 2015-08-03 03:09:18 -0600 )edit

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Asked: 2015-07-31 08:08:08 -0600

Seen: 342 times

Last updated: Aug 03 '15