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Hi,
On Thu, 28 Oct 2004, Ryan Lovett wrote:
> clients
> |
> internet
> |
> gateway (G)
> |
> _______________________________________|________________________
> | | | | | | | | | |
> __|_|__ __|_|__ __|_|__ __|_|__ | | | | | |
> | | | | | | | | other clients
> | A | | B | | C | | D |
> |_____| |_____| |_____| |_____|
>
>
> I'd like to setup an LVS for the above where A, B, C, and D are all on the
> same subnet and have two NICs. The only port I need setup is ssh. I was
> wondering if the following is feasible:
>
> - A, B, C, D are realservers.
>
> - Any client can directly access A, B, C, D.
>
> - A is the director.
>
> - When any client connects to the second interface on A, they could be
> sent to B, C, or D depending on load and all LVS traffic is sent to the
> second interfaces on B, C, and D.
>
> - B is a director failover.
>
Since A, B, C, and D are all on the same network, it is easy to use the
LVS/DR method to balance ssh sessions among them.
And, the Local Node feature can be used, so that A can be both director
and ssh server. Please read the Local Node page for more information
http://www.linuxvirtualserver.org/docs/LocalNode.html
> What has tripped me up is not understanding the same-subnet issue. As the
> very first step toward implementing this, I initially raised the second
> interface on A (different IP, same subnet) and was then able to connect to
> it via either interface. When I then lowered the second interface, I was
> still able to connect to A on either interface. (the hostnames given to
> eth0 and eth1 were both responsive even though the cable was physically
> unplugged from eth1.)
>
For the purpose above, you don't need to use the second interface at each
server.
> I believe LVS-Tun is what I should use since it fits the above contraints
> in the HOWTO. (no port remapping, *realserver network is on internet*,
> realserver default gw (g) is own router) A, B, C, and D all happen to be
> running Linux.
>
> Is it required that the second interfaces on A, B, C, and D be on a
> different (local) subnet? Otherwise, I don't see how LVS traffic can be
> managed since A, B, C, and D already have a default gateway set to G.
>
> There are clearly some larger network issues that I don't understand so I'd
> appreciate any guidance on what direction to look into.
>
> Thanks for your time,
> Ryan
Regards,
Wensong
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