[lxc-users] LXC 2.16 - vxlan.<iface> <MAC> migrated from <eth0> to <eth1>

Tue Sep 26 16:48:01 UTC 2017

Looks like I mistakenly said unicast.  In fact, we are using multicast group IP (239.0.0.1) to setup our VXLAN interfaces (please see below).  Also, in the example below, 10.250.1.21 is bound the eth0 (our management interface) and 172.18.22.21 is bound to eth1 (VXLAN interface).  We have 8 servers running thus far, and just increment the last octet to identify the server (i.e.: .21=server-01, .22=server-02, etc).

Some more detailed information:

# --------------------------------------------------
# The following script is run at boot time to setup VxLAN interfaces
# /usr/local/bin/setup_vxlans.sh <up|down>
# --------------------------------------------------
#!/bin/bash

# Script to configure VxLAN networks
ACTION="$1"

[ $ACTION == "up"   ]   && ip -4 route add 239.0.0.1 dev eth1
[ $ACTION == "down"   ] && ip -4 route del 239.0.0.1 dev eth1

for i in {1101..1130}
do
   [ $ACTION == "up"   ]  && ip link add vxlan.${i} type vxlan group 239.0.0.1 dev eth1 dstport 0 id ${i} && ip link set vxlan.${i} up
   [ $ACTION == "down" ]  && ip link set vxlan.${i} down && ip link del vxlan.${i}
done
# --------------------------------------------------

# --------------------------------------------------
# The /etc/network/interfaces file:
# --------------------------------------------------
source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
	address 10.250.1.21
	netmask 255.255.255.0
	broadcast 10.251.1.255
	gateway 10.251.1.1
	dns-nameservers 8.8.8.8 4.2.2.2
auto eth1
iface eth1 inet static
  address 172.17.22.21
  netmask 255.255.255.0
# --------------------------------------------------

# --------------------------------------------------
# Output from “lxc profile show <container>” snippet
# --------------------------------------------------
...
  limits.cpu: "2"
  limits.memory: 2000MB
  limits.memory.swap: “true"
...
devices:
  eth0:
    name: eth0
    nictype: macvlan
    parent: vxlan.1105
    type: nic
...
# --------------------------------------------------

Anything seem wrong or out of place?

Thanks,

-Ron

> On Sep 26, 2017, at 10:59 AM, Stéphane Graber <stgraber at ubuntu.com> wrote:
> 
> Hi,
> 
> Ok, so you're doing your own VXLAN youtside of LXD and then connecting
> containers directly to it.
> 
> The kernel error is very odd for unicast vxlan... there's really no
> reason for it to ever use the other interface...
> 
> So I'm assuming the 10.250.1.21 IP is on eth0 and 172.18.22.21 on eth1
> (or the reverse)? that is, you don't have both subnets on eth1.
> 
> On Tue, Sep 26, 2017 at 09:52:37AM -0400, Ron Kelley wrote:
>> Thanks Stephane.
>> 
>> Here is a “lxc network list” on the hosts:
>> 
>> rkelley at LXD-QA-Server-04:~$ lxc network list
>> +--------+----------+---------+-------------+---------+
>> |  NAME  |   TYPE   | MANAGED | DESCRIPTION | USED BY |
>> +--------+----------+---------+-------------+---------+
>> | eth0   | physical | NO      |             | 0       |
>> +--------+----------+---------+-------------+---------+
>> | eth1   | physical | NO      |             | 2       |
>> +--------+----------+---------+-------------+---------+
>> | virbr0 | bridge   | NO      |             | 0       |
>> +--------+----------+---------+-------------+————+
>> 
>> 
>> Also, we are using vxlan in unicast mode via eth1.  Each LXD server has a unicast IP address on eth1 that lives in a separate VLAN from eth0 on the directly connected network switch.  If both eth0 and eth1 were in the same VLAN, I could possible an issue.  Once a container is spun it, it is attached to a VXLAN interface off eth1 (i.e.: vxlan.1115)
>> 
>> Thus, I am scratching my head..
>> 
>> -Ron
>> 
>> 
>>> On Sep 26, 2017, at 9:02 AM, Stéphane Graber <stgraber at ubuntu.com> wrote:
>>> 
>>> On Sun, Sep 24, 2017 at 03:27:27PM -0400, Ron Kelley wrote:
>>>> Greetings all,
>>>> 
>>>> Trying to isolate a condition whereby a container providing firewall services seems to stop processing traffic for a short time.  We keep getting the below information in /var/log/syslog of the server running the firewall.  The IP addresses shown match the network interfaces of the remote LXD server running the web server.  These IPs are for the server itself, and not the container IP
>>>> 
>>>> Sep 24 15:10:25 LXD-Server-04 kernel: [144272.412154] vxlan.1104: 00:11:22:aa:66:a3 migrated from 10.250.1.21  to 172.18.22.21
>>>> Sep 24 15:10:26 LXD-Server-04 kernel: [144272.412154] vxlan.1104: 00:11:22:aa:66:a3 migrated from 172.18.22.21 to 10.250.1.21 
>>>> Sep 24 15:10:27 LXD-Server-04 kernel: [144272.412154] vxlan.1104: 00:11:22:aa:66:a3 migrated from 10.250.1.21  to 172.18.22.21
>>>> Sep 24 15:10:28 LXD-Server-04 kernel: [144272.412154] vxlan.1104: 00:11:22:aa:66:a3 migrated from 172.18.22.21 to 10.250.1.21 
>>>> Sep 24 15:10:29 LXD-Server-04 kernel: [144272.412154] vxlan.1104: 00:11:22:aa:66:a3 migrated from 10.250.1.21  to 172.18.22.21
>>>> Sep 24 15:10:30 LXD-Server-04 kernel: [144272.412154] vxlan.1104: 00:11:22:aa:66:a3 migrated from 172.18.22.21 to 10.250.1.21 
>>>> Sep 24 15:10:31 LXD-Server-04 kernel: [144272.412154] vxlan.1104: 00:11:22:aa:66:a3 migrated from 10.250.1.21  to 172.18.22.21
>>>> Sep 24 15:10:32 LXD-Server-04 kernel: [144272.412154] vxlan.1104: 00:11:22:aa:66:a3 migrated from 172.18.22.21 to 10.250.1.21 
>>>> 
>>>> Notice how they migrate from one interface to another and then back again.  Any idea as to why these messages are getting logged?
>>>> 
>>>> Thanks.
>>>> 
>>>> -Ron
>>> 
>>> Hmm, so I think I'm going to need a bit more details on the setup.
>>> Can you show the "lxc network show" for the network on both hosts?
>>> 
>>> My current guess is that you're using vxlan in multicast mode and both
>>> your hosts have two IPs on two subnets. Multicast VXLAN works on both
>>> those subnets and it can therefore see the same remote MAC on both,
>>> having it flip/flop between the two paths.
>>> 
>>> -- 
>>> Stéphane Graber
>>> Ubuntu developer
>>> http://www.ubuntu.com
>>> _______________________________________________
>>> lxc-users mailing list
>>> lxc-users at lists.linuxcontainers.org
>>> http://lists.linuxcontainers.org/listinfo/lxc-users
>> 
>> _______________________________________________
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> 
> -- 
> Stéphane Graber
> Ubuntu developer
> http://www.ubuntu.com
> _______________________________________________
> lxc-users mailing list
> lxc-users at lists.linuxcontainers.org
> http://lists.linuxcontainers.org/listinfo/lxc-users