smtp load balancer???

Chris Conn cconn at ABACOM.COM
Wed Dec 7 21:18:09 GMT 2005

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> I don't know exactly how they do it (the network guys).  I know that 
> when moving anything important we keep the old and new IP for at least 1 
> week, even if the TTL for that host has been lowered significantly (yes, 
> it applies only to that host).
> And our Windows clients have to have their DNS cache flushed AFTER the 
> Windows servers have done it, otherwise they get the old IP back...
> Maybe we just have things misconfigured, but I have no control over them 
> (other teams).
> Local ISPs that seem to override our TTL are videotron and sympatico.  
> Two biggies!
> Denis


I just tested (one of VTLs DNS servers used for cable access) 
and it behaves correctly for our TTL setting of 5 seconds.  If I remove the 
record completely, 5 seconds later it is no longer shown when I query the mx 
record for our domain.

Pity you are not involved in the actual configuration.  In any case, the DNS 
TTL can be useful, yet it is not the method we rely on for other reasons. 
But we do have it configured, just because we can.

I am quite sure that Bell and VTL do not override the TTLs because there is 
no real reason to do so, and second it would be a pain for them to do so.

Good luck with your balancing solution, and don't forget to look at SLB.


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