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Connection lost between OVS patch ports?

asked 2015-11-04 21:59:09 -0600

Steven Su gravatar image

I'm setting up Kilo KVM region and got a problem on network configuration. I have been stuck in there for a couple of days now, so any suggestions are much appreciated!

This is three a nodes environment:

kilocontroller (management network IP on eth0)

kilonetwork (management and external network IP on br-ex, Data network IP on eth1)

kilocompute (management network IP on eth0, Data network IP on eth1)

-All notes are VMs running RHEL v7.1 on vCenter v5.5.

-I’m following the KILO RHEL installation guide ( ( So both tenant and tunnel use GRE.

I'm able to provision VM successfully but VM can't get IP address, by tracking the DHCP request I found the communication lost between OVS patch ports in compute node.

For example in case of VM VM-20151104-2 , the DHCP communication chain on compute node should be:

VM-20151104-2 -> tapb2517833-13 (qbrb2517833-13) qvbb2517833-13 -> qvob2517833-13 (br-int) patch-tun -> patch-int (br-tun) gre-0a0a0114 -> eth1 ====> Network Node ......

While I saw the DHCP request on port tapb2517833-13, qvbb2517833-13, qvob2517833-13, patch-tun but it didn't reach patch-int. At the same time I saw request on eth1 on both kilocompute and kilonetwork nodes (it never goes further on network node).

So the questions are:

1) Why DHCP lost between OVS patch ports? (Yes OVS peer is there)

2) How come eth1 on kilocompute get the traffic if OVS patch connection is broken?

Here is what I have on kilocompute:

[root@kilocompute ~]# brctl show
bridge name bridge id       STP enabled interfaces
qbrb2517833-13      8000.ce00be78fda3   no      qvbb2517833-13

[root@kilocompute ~]# ovs-vsctl show
    Bridge br-tun
        fail_mode: secure
        Port br-tun
            Interface br-tun
                type: internal
        Port "gre-0a0a0114"
            Interface "gre-0a0a0114"
                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}
    Bridge br-int
        fail_mode: secure
        Port patch-tun
            Interface patch-tun
                type: patch
                options: {peer=patch-int}
        Port "qvob2517833-13"
            tag: 1
            Interface "qvob2517833-13"
        Port br-int
            Interface br-int
                type: internal
    ovs_version: "2.3.1"
[root@kilocompute ~]# 

[root@kilocompute ~]# ovs-ofctl dump-ports br-int
OFPST_PORT reply (xid=0x2): 3 ports
  port LOCAL: rx pkts=0, bytes=0, drop=0, errs=0, frame=0, over=0, crc=0
           tx pkts=20, bytes=4656, drop=0, errs=0, coll=0
  port  2: rx pkts=0, bytes=0, drop=0, errs=0, frame=0, over=0, crc=0
           tx pkts=20, bytes=4656, drop=0, errs=0, coll=0
  port  3: rx pkts=20, bytes=4656, drop=0, errs=0, frame=0, over=0, crc=0
           tx pkts=0, bytes=0, drop=0, errs=0, coll=0
[root@kilocompute ~]#

[root@kilocompute ~]# ovs-ofctl dump-flows br-int
NXST_FLOW reply (xid=0x4):
 cookie=0x0, duration=40163.854s, table=0, n_packets=20, n_bytes=4656, idle_age=37601, priority=1 actions=NORMAL
 cookie=0x0, duration=40163.770s, table=23, n_packets=0, n_bytes=0, idle_age=40163 ...
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answered 2015-11-18 21:32:16 -0600

Steven Su gravatar image

Ok I rebuild the environment and there is no such problem, it's a wired issue but I guess I will let it go for now.

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Asked: 2015-11-04 21:51:21 -0600

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Last updated: Nov 18 '15