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On Wed, Jun 14, 2000 at 02:48:12PM +0900, ??? wrote:
> I see.
> Then the only problem is that LVS-DR only receives (and routes) packets whose
> destination is itself.
> If LVS-DR takes every packet and selects an ethernet device to be used
> for routing, then it may be used to duplicate(to give high-availability
> or to balance load) network devices such as switches, routers, firewalls,
> etc.(It is the functionality of L4-switches as I know)
My understanding is that the term layer 4 switching refers to the direction
of traffic based on layer 4 of the OSI 7 layer stack instead of layer 2.
This is what LVS does.
The additional functionallity that you speak of is more to do with the fact
that a switch - being part of the switching fabric - sees all packets for
hosts that are plugged into it. A host cannot do this. We can, however,
achive high availability by monitoring other hosts and using methods such
as ip address takeover and utilising interior routing protocols such as
OSPF.
It is also possible to purchase products such as the in-switch (sorry I
don't have the URL) which basically turn your linux box into a 4-port
switch that is able to do load balancing and HA.
--
Horms
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