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Re: Server Redundancy
From: "Jason Robertson" <jason () ifuture com>
Date: Wed, 06 Aug 2003 20:05:48 -0400

If you go out and spend a few thousand you can also get Allied Telesyn 
L2-L4 products that now support Load Balancing.  Actually the rapier 
24i is about $2000 Canadian.  (I'd have to check the VAR pricing)


On 6 Aug 2003 at 22:59, Paul Vixie wrote:

Using outboard appliances for "server load balancing" is unnecessary,
and it adds more powered boxes (thus decreasing theoretical reliability).

If your upstream router can speak OSPF and is made by either Cisco or
Juniper then it will implement ECMP (equal cost multipath).  If you put
your "service address" on lo0 as an alias, and you run Zebra or GateD
on the "service hosts" which possess that alias address, then each such
host will appear to be a router toward the service address as a "stub host"
and your upstream routers will dtrt wrt flow hashing for udp or tcp traffic
(that is, the udp/tcp port number will figure into the hash function, so
you won't multipath your tcp sessions.)

This is how f-root has worked for years.  Look ma, no appliances.
Paul Vixie

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