CARP within VirtualBox Does it work?

[dweimer]

On 2012-11-29 14:47, Damien Fleuriot wrote:
> On 29 Nov 2012, at 21:07, dweimer <dweimer at dweimer.net> wrote:
>
>> On 2012-11-29 12:53, Fleuriot Damien wrote:
>>> On Nov 29, 2012, at 6:43 PM, dweimer <dweimer at dweimer.net> wrote:
>>>
>>>> I was trying to setup a test of CARP on two virtual machines 
>>>> running in VirtualBox 4.2.4r81684 I am not sure if I have something 
>>>> wrong with my CARP configuration or if VirtualBox just doesn't work 
>>>> right with it.  I can only ping the CARP interface IP address from 
>>>> the machine listed as MASTER, if I do an ifconfig carp0 down on the 
>>>> MASTER the other machine correctly switches form BACKUP to MASTER 
>>>> and then I can ping the interface from it but not from the Original 
>>>> system.
>>>>
>>>> The VirtualBox systems are both using bridged networking, and the 
>>>> host cannot ping the carp0 IP address but can ping the interface IP 
>>>> address.
>>>>
>>>> Before I go through more trouble shooting, does anyone know if 
>>>> CARP doesn't work with VirtualBox?
>>>>
>>>> carp configuration
>>>> Machine1:
>>>> ifconfig_em0="UP"
>>>> ifconfig_em0_name="LAN"
>>>> ipv4_addrs_LAN="10.20.190.201/16"
>>>> defaultrouter="10.20.111.2"
>>>> cloned_interfaces="carp0"
>>>> ifconfig_carp0="vhid 1 advskew 100 pass ReduntantCarpTest 
>>>> 10.20.190.203/16
>>>>
>>>> ifconfig carp0:
>>>> carp0 flags=49<UP,LOOPBACK,RUNNING> metric 0 mtu 1500
>>>> inet 10.20.190.203 netmask 0xffff0000
>>>> nd6 options=29<PREFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
>>>> carp: MASTER vhid 1 advbase 1 advskew 100
>>>>
>>>>
>>>> Machine2:
>>>> ifconfig_em0="UP"
>>>> ifconfig_em0_name="LAN"
>>>> ipv4_addrs_LAN="10.20.190.202/16"
>>>> defaultrouter="10.20.111.2"
>>>> cloned_interfaces="carp0"
>>>> ifconfig_carp0="vhid 1 pass ReduntantCarpTest 10.20.190.203/16
>>>>
>>>> ifconfig carp0:
>>>> carp0 flags=49<UP,LOOPBACK,RUNNING> metric 0 mtu 1500
>>>> inet 10.20.190.203 netmask 0xffff0000
>>>> nd6 options=29<PREFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
>>>> carp: BACKUP vhid 1 advbase 1 advskew 0
>>>>
>>>> FreeBSD version is 9.1RC3 on both test machines.
>>>
>>>
>>>
>>> We're using FreeBSD and CARP in virtualized environments at work,
>>> albeit not on VirtualBox but on Proxmox/KVM.
>>>
>>> First, I would advise replacing 10.20.190.203/16 with 
>>> 10.20.190.203/32
>>>
>>>
>>> I notice your carp0 is MASTER on machine1 with an advskew of 100 vs
>>> machine 2 advskew 0, same advbase.
>>> Confirm this is *after* you've set carp0 down on machine2.
>>>
>>> If both carps are up and machine1 with advskew 100 beats machine2
>>> with advskew 0, you have an additional problem.
>>>
>>>
>>> See if you have any more luck with the /32 address on carp0 anyway.
>>
>> The documentation shows the mask matching that of the interface:
>> hostname="hostb.example.org"
>> ifconfig_fxp0="inet 192.168.1.4 netmask 255.255.255.0"
>> cloned_interfaces="carp0"
>> ifconfig_carp0="vhid 2 pass testpass 192.168.1.51/24"
>>
>> This is consistent with the man page for CARP on the system as well. 
>> Regardless I tried with the /32 and had the same result as I did with 
>> the /16.  I had done various UP/DOWN on interfaces so the current 
>> MASTER was just the last one to have not been DOWN.  I think I might 
>> just copy these VMs to my VMWARE Workstation 9 install on my home PC 
>> after work tonight and see if the problem persists.
>>
>> --
>> Thanks,
>>   Dean E. Weimer
>>   http://www.dweimer.net/
>
> You wouldn't be the famous Weimer from whom weidu originates would 
> you ?
>
> Anyway back on topic, we've had problems here with masks shorter than
> /32 on carp interaces on 8.x so we changed them all to /32 and they
> work like a charm.
>
> Might you have the time to test on 8.3 with virtualbox ?
>
> I'll see if I can install 2 of these tomorrow during my lunch break
> if that's not possible for you, and reproduce your test case.

Nope that wouldn't be me, no fame here, maybe I could be infamous for 
something one one day though, I figure that would be easier to obtain 
than fame... ;)

Probably wont have time for an 8.3 test, too many other things on my 
plate right now.

-- 
Thanks,
    Dean E. Weimer
    http://www.dweimer.net/