[60346] in North American Network Operators' Group
Re: Server Redundancy
daemon@ATHENA.MIT.EDU (Jason Robertson)
Wed Aug 6 20:06:17 2003
From: "Jason Robertson" <jason@ifuture.com>
To: nanog@merit.edu
Date: Wed, 06 Aug 2003 20:05:48 -0400
In-reply-to: <g3ispa75pc.fsf@sa.vix.com>
Errors-To: owner-nanog-outgoing@merit.edu
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
>
