Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 1 Dec 2012 10:14:14 +0100
From:      Damien Fleuriot <ml@my.gd>
To:        dweimer@dweimer.net
Cc:        freebsd-questions@freebsd.org
Subject:   Re: CARP within VirtualBox Does it work?
Message-ID:  <CAE63ME7xj8d4VSs4mDckXNkXvjGe4tXHYKrVh62QxeZu19=koA@mail.gmail.com>
In-Reply-To: <c16202554b7da41ef738dc7fadf56a69@dweimer.net>
References:  <737f4b1c8bff13850af119f917ed811c@dweimer.net> <9232DDFC-F40B-4914-A92D-3B5D9C1ECE5F@my.gd> <a36ea7e237eb291f7fabf7daa7c3f8ab@dweimer.net> <c16202554b7da41ef738dc7fadf56a69@dweimer.net>

next in thread | previous in thread | raw e-mail | index | archive | help
On 30 November 2012 20:44, dweimer <dweimer@dweimer.net> wrote:
> 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.
>


Well, it definitely works here for us on Proxmox/KVM.

When you tcpdump on your either host, do you see the CARP
advertisements from the other ?


FInd below the advertisements as seen from our CARP backup firewall:
$ sudo tcpdump -ni vlan14 vrrp
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on vlan14, link-type EN10MB (Ethernet), capture size 96 bytes
10:11:09.084568 IP 195.158.240.[snip] > 224.0.0.18: VRRPv2,
Advertisement, vrid 114, prio 50, authtype none, intvl 1s, length 36
10:11:10.282826 IP 195.158.240.[snip] > 224.0.0.18: VRRPv2,
Advertisement, vrid 114, prio 50, authtype none, intvl 1s, length 36
10:11:11.481075 IP 195.158.240.[snip] > 224.0.0.18: VRRPv2,
Advertisement, vrid 114, prio 50, authtype none, intvl 1s, length 36



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAE63ME7xj8d4VSs4mDckXNkXvjGe4tXHYKrVh62QxeZu19=koA>