ttl for ns

Niels Bakker niels=nanog at bakker.net
Fri Aug 13 15:33:29 UTC 2004


* mcgehrin at reverse.net (Matthew McGehrin) [Fri 13 Aug 2004, 16:46 CEST]:
> 1.    It's a financial issue. In the event of an emergency or an server 
> failure, how many hours can you financially be offline. Are your customers 
> willing to wait up to 2 days for their DNS caches to update with the new IP 
> address?

In the event of a server failure I suggest you add its IP address as an
alias to a non-deceased host.  You kept backups of your master zone files
on another machine, didn't you?


> A very busy domain might benefit from having a higher TTL value for their 
> nameserver's but having a lower TTL for hosts, so that you minimize your 
> downtime, in the event of a server failure. For example, when Akamai was 
> having DNS issues, content providers with low TTL's were able to switch to 
> secondary nameservers faster, than zones with using a higher TTL.

Assuming you're talking about a specific incident not too long ago:

To me it looked more like those who had actually spent thought on what
to do in the case of a large, longer Akamai failure had less impact when
that failure occurred.


	-- Niels.



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