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br-tun and br-int are not UP but still VMs are pinging [closed]

asked 2016-10-11 08:53:11 -0500

udayutkarsh gravatar image

updated 2016-10-12 08:52:06 -0500

Hi, I am new to openstack. I have a 4-node set up all installed on separate rhel7.1 vms. Its an RDO package kilo version of openstack. I have a controller, network and 2 compute nodes. I have 2 VMs running on each compute node. VM1 on compute1 has ip 10.10.10.3 and VM2 on compute node 3 has IP 20.20.20.3. Both VMs are created by admin user and are connected by an internal router. The network type is vxlan. When I ping from VM1 to VM2 its successful. According to this link (http://docs.openstack.org/kilo/networ...) the packet flow sequence should be like as under:

VM1==>tap device==>linux bridge==>br-int ==> br-tun ==> eth0(br-ex) and then it goes to network node's br-tun==>br-int here it should get routed and should go to compute node2 in the same but reverse sequence.

But when I see these bridges like br-int and br-tun they are down and not running on each compute node.

COMPUTE1::
==============
[root@compute1 ~(keystone_admin)]# ifconfig
br-ex: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.123.12  netmask 255.255.255.0  broadcast 192.168.123.255
        inet6 fe80::7840:30ff:fe63:ea4a  prefixlen 64  scopeid 0x20<link>
        ether 7a:40:30:63:ea:4a  txqueuelen 0  (Ethernet)
        RX packets 6174  bytes 899439 (878.3 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 6385  bytes 917134 (895.6 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet6 fe80::5054:ff:fe42:919  prefixlen 64  scopeid 0x20<link>
        ether 52:54:00:42:09:19  txqueuelen 1000  (Ethernet)
        RX packets 6527  bytes 917795 (896.2 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 6384  bytes 917136 (895.6 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 0  (Local Loopback)
        RX packets 1417  bytes 74407 (72.6 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1417  bytes 74407 (72.6 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

qbr348457a5-3d: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet6 fe80::fc0f:beff:fed0:422c  prefixlen 64  scopeid 0x20<link>
        ether e2:37:1c:db:cc:fa  txqueuelen 0  (Ethernet)
        RX packets 8  bytes 508 (508.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 8  bytes 648 (648.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

qvb348457a5-3d: flags=4419<UP,BROADCAST,RUNNING,PROMISC,MULTICAST>  mtu 1500
        inet6 fe80::e037:1cff:fedb:ccfa  prefixlen 64  scopeid 0x20<link>
        ether e2:37:1c:db:cc:fa  txqueuelen 1000  (Ethernet)
        RX packets 10  bytes 788 (788.0 B)
        RX errors 0  dropped 0  overruns 0  frame ...
(more)
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Closed for the following reason the question is answered, right answer was accepted by udayutkarsh
close date 2018-01-27 19:01:29.052857

3 answers

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answered 2016-10-12 12:33:23 -0500

darragh-oreilly gravatar image

updated 2016-10-18 10:42:28 -0500

This is normal. Ifconfig is showing interfaces br-int and br-tun - not bridges. These are OVS ports that get created when the bridges were created. But they are not used by the neutron-openvswitch-agent, so it is best that you leave them down. They are trunk ports, but tcpdumping them won't show much except broadcasts and floods, because the bridge learns where the macs are - ovs-appctl fdb/show br-int

Note OVS is a little different than Linux bridges in this regard. With linux bridge, the interface with the same name as the bridge needs to be up, or the bridge will not forward.

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Comments

Thanks for the reply..i have another query. Since I have two isolated networks and 2 VMs, one on each compute node. if integration and tunnel bridges are working as expected, what is the traffic path being followed from compute1====>network-node=====> compute2?

udayutkarsh gravatar imageudayutkarsh ( 2016-10-12 23:21:47 -0500 )edit

It's better to open another question on ask.openstack.org so that people with the same concern can find it.

Bernd Bausch gravatar imageBernd Bausch ( 2016-10-13 01:26:45 -0500 )edit

Sure, I ll open another question but I want to understand what are the mistakes that i have done or what are the changed do i need to make in my cloud for it to work in the manner described here:: "http://docs.openstack.org/kilo/networking-guide/scenario_legacy_ovs.html#packet-flow" scenario 3

udayutkarsh gravatar imageudayutkarsh ( 2016-10-13 06:40:54 -0500 )edit

I have opened another question https://ask.openstack.org/en/question...

udayutkarsh gravatar imageudayutkarsh ( 2016-10-13 08:06:05 -0500 )edit
0

answered 2016-10-11 16:37:04 -0500

VSR gravatar image

Please issue command "ip link" and "ip addr" and "brctl show" and report back.

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Hi, i was not able to post the details here as the character size limit is less. I have edited the original question itself to accommodate the info you have asked me.

udayutkarsh gravatar imageudayutkarsh ( 2016-10-12 06:10:58 -0500 )edit
0

answered 2016-10-11 11:21:06 -0500

hkominos gravatar image

They are running. I think It is just a bug that shows that they are down.

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In that case also why packets are not going out of compute node's physical interface eth0 and arriving on network node. i have fired command "tcpdump icmp -i any " on my compute node. I cannot see any icmp packets arriving.

udayutkarsh gravatar imageudayutkarsh ( 2016-10-12 06:13:20 -0500 )edit

hey utkarsh, Are you using the self service or the provider network scenario? Also which is the ML2 plugin that you are using. Also paste the contents of openvswitch_agent.ini & ml2_conf.ini. Assuming you are using openvswitch.

DarkKnight gravatar imageDarkKnight ( 2016-10-12 06:18:09 -0500 )edit

Hi, I have pasted the contents of ovs_neutron_plugin.ini file. I have configured br-ex for provider flat/vlan but but I have created two tenant level networks and vms. Actually I am tracing east-west traffic scenario only

udayutkarsh gravatar imageudayutkarsh ( 2016-10-12 08:55:25 -0500 )edit

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Asked: 2016-10-11 08:53:11 -0500

Seen: 500 times

Last updated: Oct 18 '16