Re: Fail-over on different subnets

On 10/30/06, Yu Safin <[email protected]> wrote:
> I got my keepalived configuration to work when my eth0 in both MASTER
> and BACKUP are in the same subnet e.g. 192.168.10.11 and 192.168.10.12
> sharing a VIP e.g. 192.168.10.10 (mask 255.255.255.0).
> My requirement is that MASTER and BACKUP be setup in two different
> subnets separated by a CISCO ROUTER.  In this case etho for MASTER is
> 192.168.10.11 and my eth0 for BACKUP is 192.168.20.11  (mask
> 255.255.255.0).  They can see each other via the ROUTER (each subnet
> in its own Interface in the router).
>
> I tested the setup with the VIP in the MASTER segment (192.168.10.10)
> and the VIP is moved back and forth depending on the availability of
> eth0 in MASTER.   However, my remote clients cannot use the VIP when
> the BACKUP takes control.
>
> I know this is a network issue and was hoping I would get some help
> from this list.
> p.s. we use keepalived just to fail over services between MASTER and
> BACKUP (active-passive).
>
I can get this configuration to work by using quagga (zebra/ospfd) to
advertise the VIP to the router (OSPF).
I came across a discussion on the topic of multiple subnets at
http://www.in-addr.de/pipermail/lvs-users/2003-august/009335.html.
The concept of a "sip" is introduced for the working IP.  This "sip"
is the one that points to the "vip" in the router.  An interesting
concept but I have not tested it yet.
I would prefer not to have to run "quagga" so I will explore the "sip" concept.
If anybody in this list have an opinion on the subject, I would love
to hear from you.

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