[ovs-discuss] Issue when using local_ip with VXLAN tunnels in OVS

Flavio Leitner fbl at sysclose.org
Tue Nov 6 18:56:01 UTC 2018


On Tue, Nov 06, 2018 at 11:51:49AM -0500, Siva Teja ARETI wrote:
> Hi Greg,
> 
> Thanks for looking into this.
> 
> I have two VMs in my setup each with two interfaces. Trying to setup the
> VXLAN tunnels across these interfaces which are in different subnets. A
> docker container is attached to ovs bridge using ovs-docker utility on each
> VM and doing a ping from one container to another.

Do you see any interesting related messages in 'dmesg' output or in 
ovs-vswitchd.log?

If I recall correctly, the "ip l" should show the vxlan dev named
vxlan_sys_<port>.

fbl

> 
> *VM1 details:*
> 
> [root at vm1 ~]# ip a
> .......
> 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state
> UP qlen 1000
>     link/ether 52:54:00:b8:05:be brd ff:ff:ff:ff:ff:ff
>     inet 30.30.0.59/24 brd 30.30.0.255 scope global dynamic eth1
>        valid_lft 3002sec preferred_lft 3002sec
>     inet6 fe80::5054:ff:feb8:5be/64 scope link
>        valid_lft forever preferred_lft forever
> 4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state
> UP qlen 1000
>     link/ether 52:54:00:f0:64:37 brd ff:ff:ff:ff:ff:ff
>     inet 20.20.0.183/24 brd 20.20.0.255 scope global dynamic eth2
>        valid_lft 3248sec preferred_lft 3248sec
>     inet6 fe80::5054:ff:fef0:6437/64 scope link
>        valid_lft forever preferred_lft forever
> .......
> [root at vm1 ~]# ovs-vsctl show
> ff70c814-d1b0-4018-aee8-8b635187afee
>     Bridge "testbr0"
>         Port "gre0"
>             Interface "gre0"
>                 type: gre
>                 options: {local_ip="20.20.0.183", remote_ip="30.30.0.193"}
>         Port "testbr0"
>             Interface "testbr0"
>                 type: internal
>         Port "2cfb62a9b0f04_l"
>             Interface "2cfb62a9b0f04_l"
>     ovs_version: "2.9.2"
> [root at vm1 ~]# ip rule list
> 0:      from all lookup local
> 32765:  from 20.20.0.183 lookup siva
> 32766:  from all lookup main
> 32767:  from all lookup default
> [root at vm1 ~]# ip route show table siva
> default dev eth2 scope link src 20.20.0.183
> [root at vm1 ~]# ######################### A docker container is attached to
> ovs bridge using ovs-docker utility
> [root at vm1 ~]# docker ps
> CONTAINER ID        IMAGE               COMMAND             CREATED
>      STATUS              PORTS               NAMES
> be4ab434db99        busybox             "sh"                5 days ago
>     Up 5 days                               admiring_euclid
> [root at vm1 ~]# nsenter -n -t `docker inspect be4 --format={{.State.Pid}}` --
> ip a
> 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
>     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
>     inet 127.0.0.1/8 scope host lo
>        valid_lft forever preferred_lft forever
>     inet6 ::1/128 scope host
>        valid_lft forever preferred_lft forever
> 2: gre0 at NONE: <NOARP> mtu 1476 qdisc noop state DOWN qlen 1
>     link/gre 0.0.0.0 brd 0.0.0.0
> 3: gretap0 at NONE: <BROADCAST,MULTICAST> mtu 1462 qdisc noop state DOWN qlen
> 1000
>     link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
> 9: eth0 at if10: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
> state UP qlen 1000
>     link/ether 22:98:41:0f:e8:50 brd ff:ff:ff:ff:ff:ff link-netnsid 0
>     inet 70.70.0.10/24 scope global eth0
>        valid_lft forever preferred_lft forever
>     inet6 fe80::2098:41ff:fe0f:e850/64 scope link
>        valid_lft forever preferred_lft forever
> 
> 
> *VM2 details:*
> 
> [root at vm2 ~]# ip a
> ........
> 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state
> UP qlen 1000
>     link/ether 52:54:00:79:ef:92 brd ff:ff:ff:ff:ff:ff
>     inet 30.30.0.193/24 brd 30.30.0.255 scope global dynamic eth1
>        valid_lft 2406sec preferred_lft 2406sec
>     inet6 fe80::5054:ff:fe79:ef92/64 scope link
>        valid_lft forever preferred_lft forever
> 4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state
> UP qlen 1000
>     link/ether 52:54:00:05:93:7c brd ff:ff:ff:ff:ff:ff
>     inet 20.20.0.64/24 brd 20.20.0.255 scope global dynamic eth2
>        valid_lft 2775sec preferred_lft 2775sec
>     inet6 fe80::5054:ff:fe05:937c/64 scope link
>        valid_lft forever preferred_lft forever
> .......
> [root at vm2 ~]# ovs-vsctl show
> b85514db-3f29-4f7a-9001-37d70adfca34
>     Bridge "testbr0"
>         Port "gre0"
>             Interface "gre0"
>                 type: gre
>                 options: {local_ip="30.30.0.193", remote_ip="20.20.0.183"}
>         Port "a0769422cfc04_l"
>             Interface "a0769422cfc04_l"
>         Port "testbr0"
>             Interface "testbr0"
>                 type: internal
>     ovs_version: "2.9.2"
> [root at vm2 ~]# ip rule list
> 0:      from all lookup local
> 32766:  from all lookup main
> 32767:  from all lookup default
> [root at vm2 ~]# ######################### A docker container is attached to
> ovs bridge using ovs-docker utility
> [root at vm2 ~]# docker ps
> CONTAINER ID        IMAGE               COMMAND             CREATED
>      STATUS              PORTS               NAMES
> 86214f0d99e8        busybox:latest      "sh"                5 days ago
>     Up 5 days                               peaceful_snyder
> [root at vm2 ~]# nsenter -n -t `docker inspect 862 --format={{.State.Pid}}` --
> ip a
> 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
>     link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
>     inet 127.0.0.1/8 scope host lo
>        valid_lft forever preferred_lft forever
>     inet6 ::1/128 scope host
>        valid_lft forever preferred_lft forever
> 2: gre0 at NONE: <NOARP> mtu 1476 qdisc noop state DOWN qlen 1
>     link/gre 0.0.0.0 brd 0.0.0.0
> 3: gretap0 at NONE: <BROADCAST,MULTICAST> mtu 1462 qdisc noop state DOWN qlen
> 1000
>     link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
> 9: eth0 at if10: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
> state UP qlen 1000
>     link/ether ae:ac:14:7a:40:5f brd ff:ff:ff:ff:ff:ff link-netnsid 0
>     inet 70.70.0.20/24 scope global eth0
>        valid_lft forever preferred_lft forever
>     inet6 fe80::acac:14ff:fe7a:405f/64 scope link
>        valid_lft forever preferred_lft forever
> 
> With this configuration, if I do a ping from docker container on VM1 to
> docker container on VM2 it works.
> 
> [root at vm1 ~]# nsenter -n -t `docker inspect be4 --format={{.State.Pid}}` --
> ping 70.70.0.20
> PING 70.70.0.20 (70.70.0.20) 56(84) bytes of data.
> 64 bytes from 70.70.0.20: icmp_seq=1 ttl=64 time=0.831 ms
> 64 bytes from 70.70.0.20: icmp_seq=2 ttl=64 time=0.933 ms
> 64 bytes from 70.70.0.20: icmp_seq=3 ttl=64 time=0.564 ms
> ^C
> --- 70.70.0.20 ping statistics ---
> 3 packets transmitted, 3 received, 0% packet loss, time 2001ms
> rtt min/avg/max/mdev = 0.564/0.776/0.933/0.155 ms
> 
> And the traffic is as expected on VM2.
> 
> [root at vm2 ~]# tcpdump -n -i any host 20.20.0.183
> 
> 
> tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
> listening on any, link-type LINUX_SLL (Linux cooked), capture size 262144
> bytes
> 16:37:32.262553 IP 20.20.0.183 > 30.30.0.193: GREv0, length 102: IP
> 70.70.0.10 > 70.70.0.20: ICMP echo request, id 28158, seq 1, length 64
> 16:37:32.262835 IP 30.30.0.193 > 20.20.0.183: GREv0, length 102: IP
> 70.70.0.20 > 70.70.0.10: ICMP echo reply, id 28158, seq 1, length 64
> 16:37:33.263211 IP 20.20.0.183 > 30.30.0.193: GREv0, length 102: IP
> 70.70.0.10 > 70.70.0.20: ICMP echo request, id 28158, seq 2, length 64
> 16:37:33.263374 IP 30.30.0.193 > 20.20.0.183: GREv0, length 102: IP
> 70.70.0.20 > 70.70.0.10: ICMP echo reply, id 28158, seq 2, length 64
> 16:37:34.264159 IP 20.20.0.183 > 30.30.0.193: GREv0, length 102: IP
> 70.70.0.10 > 70.70.0.20: ICMP echo request, id 28158, seq 3, length 64
> 16:37:34.264252 IP 30.30.0.193 > 20.20.0.183: GREv0, length 102: IP
> 70.70.0.20 > 70.70.0.10: ICMP echo reply, id 28158, seq 3, length 64
> 
> But when I change the tunnel type to vxlan, ping fails.
> 
> [root at vm1 ~]# ovs-vsctl del-port testbr0 gre0
> [root at vm1 ~]# ovs-vsctl add-port testbr0 vxlan0 -- set interface vxlan0
> type=vxlan options:local_ip=20.20.0.183 options:remote_ip=30.30.0.193
> options:dst_port=4789
> [root at vm1 ~]# ovs-vsctl show
> ff70c814-d1b0-4018-aee8-8b635187afee
>     Bridge "testbr0"
>         Port "testbr0"
>             Interface "testbr0"
>                 type: internal
>         Port "vxlan0"
>             Interface "vxlan0"
>                 type: vxlan
>                 options: {dst_port="4789", local_ip="20.20.0.183",
> remote_ip="30.30.0.193"}
>         Port "2cfb62a9b0f04_l"
>             Interface "2cfb62a9b0f04_l"
>     ovs_version: "2.9.2"
> 
> [root at vm2 ~]# ovs-vsctl del-port testbr0 gre0
> [root at vm2 ~]# ovs-vsctl add-port testbr0 vxlan0 -- set interface vxlan0
> type=vxlan options:local_ip=30.30.0.193 options:remote_ip=20.20.0.183
> options:dst_port=4789
> [root at vm2 ~]# ovs-vsctl show
> b85514db-3f29-4f7a-9001-37d70adfca34
>     Bridge "testbr0"
>         Port "a0769422cfc04_l"
>             Interface "a0769422cfc04_l"
>         Port "vxlan0"
>             Interface "vxlan0"
>                 type: vxlan
>                 options: {dst_port="4789", local_ip="30.30.0.193",
> remote_ip="20.20.0.183"}
>         Port "testbr0"
>             Interface "testbr0"
>                 type: internal
>     ovs_version: "2.9.2"
> 
> Ping fails with this setup
> 
> [root at vm1 ~]# nsenter -n -t `docker inspect be4 --format={{.State.Pid}}` --
> ping 70.70.0.20
> PING 70.70.0.20 (70.70.0.20) 56(84) bytes of data.
> ^C
> --- 70.70.0.20 ping statistics ---
> 6 packets transmitted, 0 received, 100% packet loss, time 4999ms
> 
> Expected traffic is not seen on VM2
> 
> [root at vm2 ~]# tcpdump -n -i any host 20.20.0.183
> 
> 
> tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
> listening on any, link-type LINUX_SLL (Linux cooked), capture size 262144
> bytes
> ^C
> 0 packets captured
> 0 packets received by filter
> 0 packets dropped by kernel
> 
> Kindly let me know if you need more information.
> 
> Siva Teja.
> 
> On Tue, Nov 6, 2018 at 10:49 AM Gregory Rose <gvrose8192 at gmail.com> wrote:
> 
> >
> > On 11/5/2018 6:10 PM, Siva Teja ARETI wrote:
> >
> > Hi,
> >
> > I am trying to use local_ip option for a VXLAN tunnel using ovs but it
> > does not seem to work. The same works when I use GRE tunnel. I also found a
> > previous discussion from another user who tried the exact same approach.
> > Here is the link to the discussion
> >
> > *https://www.mail-archive.com/ovs-discuss@openvswitch.org/msg03643.html
> > <https://www.mail-archive.com/ovs-discuss@openvswitch.org/msg03643.html>*
> >
> > I am unable to find any working resolution at the end of this discussion.
> > Could you please help?
> >
> >
> > I looked into that but was never able to set up a configuration like the
> > one in that discussion and could
> > not repro the bug.
> >
> > Please provide some details on your usage, configuration and steps to
> > repro and I can look into it.
> >
> > Thanks,
> >
> > - Greg
> >
> >
> > I am using ovs 2.9.2
> >
> > [root at localhost ~]# ovs-vsctl --version
> > ovs-vsctl (Open vSwitch) 2.9.2
> > DB Schema 7.15.1
> >
> > Thanks,
> > Siva Teja.
> >
> >
> > _______________________________________________
> > discuss mailing listdiscuss at openvswitch.orghttps://mail.openvswitch.org/mailman/listinfo/ovs-discuss
> >
> >
> >

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-- 
Flavio



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