[dnsop] DNS Anycast revisited (fwd)

Wed May 4 04:36:45 UTC 2005

On May 3, 2005, at 10:28 PM, Nicholas Suan wrote:

> In the previous paragraph Vixie said:
>
>> while i'm on the subject, i also remain convinced that using  
>> anycast to do
>> distributed load balancing for applications like WWW, on the  
>> assumption
>> that the path you heard a dns query on is instructive as to what  
>> content
>> would be best to answer with, is silly, and will more often do  
>> harm or do
>> nothing than do good.  (and i've told akamai and speedera this  
>> many times.)
>> ("but it makes for great marketing slideware.")
>>
>
> In other words this is a bad idea:
>
> [FT at fenrir FT]$ dig a248.e.akamai.net @69.45.79.10
>
> ;; ANSWER SECTION:
> a248.e.akamai.net.      20      IN      A       80.67.72.214
> a248.e.akamai.net.      20      IN      A       80.67.72.201
>
> FT at inuyasha:~$ dig a248.e.akamai.net @69.45.79.10
>
> ;; ANSWER SECTION:
> a248.e.akamai.net.      20      IN      A       69.45.79.15
> a248.e.akamai.net.      20      IN      A       69.45.79.16
>
> While I'm not a mind reader, It seems he's saying that, since  
> Ultradns doesn't use anycast to do this, it is an example of 'good  
> anycast.'

I'm not a mind reader either, but I read English.  (Well, I try  
sometimes. :)  Paul said:

<quote>
i also remain convinced that using anycast to do distributed load  
balancing for applications like WWW, ... is silly, and will more  
often do harm or do nothing than do good.  (and i've told akamai and  
speedera this many times.)
</quote>

The fact your digs returned different IPs for the same hostname has  
_nothing_ to do with anycast.

Whether (or not) UltraDNS doing this (or not) is good (or not) seems,  
to me at least, to be apples & oranges.

-- 
TTFN,
patrick