Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 30 Nov 2012 13:44:48 -0600
From:      dweimer <dweimer@dweimer.net>
To:        <freebsd-questions@freebsd.org>
Subject:   Re: CARP within VirtualBox Does it =?UTF-8?Q?work=3F?=
Message-ID:  <c16202554b7da41ef738dc7fadf56a69@dweimer.net>
In-Reply-To: <a36ea7e237eb291f7fabf7daa7c3f8ab@dweimer.net>
References:  <737f4b1c8bff13850af119f917ed811c@dweimer.net> <9232DDFC-F40B-4914-A92D-3B5D9C1ECE5F@my.gd> <a36ea7e237eb291f7fabf7daa7c3f8ab@dweimer.net>

Next in thread | Previous in thread | Raw E-Mail | Index | Archive | Help
On 2012-11-29 14:07, dweimer wrote:
> On 2012-11-29 12:53, Fleuriot Damien wrote:
>> On Nov 29, 2012, at 6:43 PM, dweimer <dweimer@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.

The behavior definitely changed going from VirtualBox to VMWare, the 
only change in my configuration was the IP addresses to match the home 
network.  However now I can talk to the carp interface form other 
machines, but they receive two response one from each of the test 
systems.  TCPDUMP shows that they are each seeing the others broadcasts, 
but for some reason they are both running as MASTER.  If you run a 
DOWN/UP on the interface, it briefly shows as BACKUP before switching to 
MASTER.  I tried with both /24 subnet of my home network, and setting 
the carp0 interface to /32, both behaved the same.  Any one have any 
other ideas, as to whether this comes down to a Virtual Network Issue, 
or a setup issue on my part.


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



Want to link to this message? Use this URL: <http://docs.FreeBSD.org/cgi/mid.cgi?c16202554b7da41ef738dc7fadf56a69>