Server Redundancy

Thu Aug 7 00:05:48 UTC 2003

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)

Jason

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
> 