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Re: How to loadbalancing using 2 ISPs?



On 28 Nov 2002 14:40:51 EST, Chris Maxwell writes:
>Without an ASN to peer with two providers (like Chuck is doing), you
>cannot get anywhere near true load balancing ... even with an ASN, async
>routing is fairly normal

Well, "not possible" probably isn't really true, although I haven't 
 seen anyone implementing such a beast yet (only vaguely recall 
 Stonesoft marketeers talking about plans for it).

What you could do is:
Monitor interface load on your gateway/NAT-machine. Assign new outgoing 
 connections to the one having a lower load, NATing it behind that 
 interfaces official IP-address. Add some semi-intelligence on what 
 connections are likely to produce what traffic, probably self-building 
 sort-of a database with historic data. For incoming stuff, your best bet 
 would probably making business with akamai or somesuch.

Yes, ugly kludge, no question there. Yes, would probably break _many_
 things in more new and interesting ways than I'd want to be able to 
 imagine. Yes, would be more-or-less un-debuggable.

But could be done.

And, besides, for just using two pipes of different ISPs you don't need 
 an ASN, just PI-addresspace (which, curiously, is what RIPE suggests if 
 you just want to use two pipes and do nothing more complicated because 
 it saves on those scarce  ASNs). Without an ASN you just have less
 control (or have to have more clueful and willing ISPs to let you do
 ugly stuff with their routing).

cheers,
&rw
-- 
-- A lady came up to me on the street and pointed at my leather jacket.
-- 'You know a cow was murdered for that jacket?' she sneered.
-- I replied in a psychotic tone, 'I didn't know there
-- were any witnesses. Now I'll have to kill you too.'