smtp load balancer???

Chris Conn cconn at ABACOM.COM
Wed Dec 7 20:48:18 GMT 2005

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> Chris,
> I've been told (and have verified it on many occasions) that big ISPs 
> don't care about the TTL we define for our DNS entries.  They will 
> override our TTL with their default value which could be as high as many 
> days...

Remember I am suggesting SLB over DNS...


I am curious on verifying your claim as well as the other gentleman.  Are 
you defining the TTL on a per-record basis?  How are you doing this?

Currently your TTL for record is 1 do you go 
about overriding this?

I do not believe that any ISP is "overriding" TTLs.  I would believe 
non-compliant DNS servers perhaps.   But my testing locally here of 
temporarily disabling my secondary DNS record for my MX shows that Microsoft 
clients are flawlessly balancing to the remaining host.

Your mileage may vary, but it works here.  Again I repeat that I do not 
depend on this to spread load however, SLB does that nicely for me.


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