bad horizontal referral ?

[Kevin Darcy]

Jean-François Leroux wrote:
> Thanks for the explanation, Kevin. If I may ask, what means
> 'horizontal' in the message? I've had a look in my DNS & Bind book but
> couldn't find anything about it...
> And while I'm thinking of it, how can I know which server refers me to
> a wrong address? Is this possible ?
>
>
> 2008/3/12, Kevin Darcy <kcd at chrysler.com>:
>   
>> Jean-François Leroux wrote:
>>  > Hi,
>>  > doing a trace with dig today I got a 'BAD (HORIZONTAL) REFERRAL'
>>  > message, with the correct answer though.
>>  >  What does this mean ?
>>  >
>>  >
>>  >
>>
>> Referrals should be "down" not "across". If you're resolving www.foo.com
>>  iteratively and along the way a delegated nameserver for foo.com refers
>>  you to blah.com, that's a useless referral because it doesn't get you
>>  any closer to resolving the name.
>>
>>  Dig probably got the correct answer because it gave up on the broken
>>  nameserver and tried a different one.
>>     
"Horizontal" means at the same level of the hierarchy. The DNS namespace 
is often viewed as being tree-like, with the "root" at the top and each 
level of subdomain extending downwards. If a referral is "across" rather 
than "down", it's "horizontal" instead of "vertical".

So many prepositions, so little time...

                                                                         
      - Kevin