[ovs-discuss] ARP Behavior in XenServer Host

[David Erickson]

On 12/1/2011 12:01 PM, Ben Pfaff wrote:
> On Wed, Nov 30, 2011 at 06:18:15PM -0800, David Erickson wrote:
>> I think I've run into another semi-related issue with inband.  I
>> recently changed the fail mode of my OVS instances from standalone
>> to secure because I wanted them to continue using the rules that had
>> been set in the event the controller died or needed restarting.
>> This had the unfortunate side effect that if the controller is down
>> long enough then the box can lose its DHCP lease, and be unable to
>> get a new one because DHCP requests are trying to be sent to the
>> controller, but the switch isn't able to connect to the controller
>> without an address, ie:
>>
>> Nov 30 21:04:52 localhost dhclient: DHCPDISCOVER on xenbr0 to
>> 255.255.255.255 port 67 interval 4
>> Nov 30 21:04:56 localhost dhclient: No DHCPOFFERS received.
>> Nov 30 21:04:56 localhost dhclient: No working leases in persistent
>> database - sleeping.
>> Nov 30 21:04:58 localhost ovs-vswitchd:
>> 789878|stream_tcp|ERR|tcp:192.168.1.11:6633: connect: Network is
>> unreachable
>>
>> What is the behavior of the inband rules when the switch is in
>> secure mode and has lost connection to the controller?
> No different from any other time.
>
>> It seems to me like they are being ignored, or at least the DHCP
>> rule doesn't seem to be working.
> Please investigate further.  I would start by finding out whether the
> DHCP requests are making it out on the wire, then if they are, whether
> DHCP replies are visible coming back across the wire.

Ya the requests aren't making it onto the wire.

-D