incorrect info from root servers

[Barry Margolin]

In article <38A59481.C179924A at mindspring.com>,
Brock Sides  <philarete at mindspring.com> wrote:
>Yesterday, I noticed that mail for midsouth.rr.com was queueing up on my
>mail server instead of being delivered. I quickly discovered the reason:
>my nameservers were caching an incorrect A record for
>"mail.midsouth.rr.com": 24.92.24.1 instead of 24.92.68.1.
>
>With a little more investigation, I determined where I was getting this
>incorrect information: from the root servers themselves!
>
>More investigation revealed what the problem is: "mail.midsouth.rr.com"
>is registered as a HOST through Network Solutions, with the IP address
>24.92.64.1. So the root servers think they know the correct IP address,
>and they are not referring me to ns1.midsouth.rr.com to get the correct
>information.
>
>Now that I've found the source of the problem, my question is this: Why
>are no other name servers having this problem? Every other name server I
>hit (other than the ones I run) is returning the correct A record. They
>appear to be ignoring what the root servers say, asking
>ns1.midsouth.rr.com, and getting the correct information.

It depends on whether they've recently had to look up anything else in the
domain before looking up mail.midsouth.rr.com.  If they did, they would
have cached the NS records for the domain, and not gone to the root
servers.  But if they don't have any NS records cached for midsouth.rr.com
or rr.com, they'll start at the root servers.

-- 
Barry Margolin, barmar at bbnplanet.com
GTE Internetworking, Powered by BBN, Burlington, MA
*** DON'T SEND TECHNICAL QUESTIONS DIRECTLY TO ME, post them to newsgroups.
Please DON'T copy followups to me -- I'll assume it wasn't posted to the group.