large organization nameservers sending icmp packets to dns servers.

Doug Barton dougb at
Thu Aug 9 22:56:20 UTC 2007

On Mon, 6 Aug 2007, Drew Weaver wrote:

>        Is it a fairly normal practice for large companies such as Yahoo! 
> And Mozilla to send icmp/ping packets to DNS servers? If so, why? And a 
> related question would be from a service provider standpoint is there 
> any reason to deny ICMP/PING packets to name servers within your 
> organization?

If someone else mentioned this I didn't see it, so I think it's worthwhile 
to point out that in the case of Yahoo! at least the pinging isn't done by, but rather it's done by Akamai after you get to the point 
in the chain where the "real" answer is going to come from one of their 

Someone else already did point out that in spite of the existence of 
outliers, the shape of the bell-shaped curve remains the same, and if this 
method didn't actually work then it wouldn't be in such widespread use.




 	If you're never wrong, you're not trying hard enough

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