Lame delegation to server with cached NS data.

[Two Dog]

Thanks for putting that into perspective.  I was a little confused
about the "loop"  but you cleared it up.


On Mon, 13 Sep 2004 20:29:30 -0400, Kevin Darcy <kcd at daimlerchrysler.com> wrote:
> 
> 
> Two Dog wrote:
> 
> >Hello,
> >
> >While this is more of a DNS question than a BIND question I do
> >appreciate your help with this, as I'm having some trouble
> >understanding it.
> >
> >The domain in question is wecdsb.on.ca when I query it returns an
> >answer only occasionally. This domain is not under our control or do I
> >have any authority over it.
> >
> >I did a traversal of the domain at http://www.squish.net/dnscheck and
> >saw that one of the name servers for that domain ns4.dm.egate.net is
> >"Loop Detected! Probable cause is lame delegation to server with
> >cached NS data"
> >
> >As far as I understand it that means the egate.net name server is
> >sending out the request for a question it already has the answer too
> >thereby creating a loop.  Would that be correct?  If so what could one
> >do to resolve that issue?
> >
> >I've also tried looking up this domain against other name servers and
> >they too occasionally return a timed out result or no host.
> >
> >How can I educate this customer that the 'problem' in question does
> >not exist on our network but his network layout?
> >
> Calling this a "loop" is I think a little misleading. The wecdsb.on.ca
> domain has been delegated to ns4.dm.egate.net (as well as to
> ns.wecdsb.on.ca), but ns4.dm.egate.net is not authoritative for the
> zone. This is a typical "lame" delegation, then. Most nameservers
> implementations will recognize this lameness and simply ignore what
> ns4.dm.egate.net has to say about the zone. What this boils down to,
> however, is there is exactly *one* working nameserver for the domain
> (ns.wecdsb.on.ca). If that nameserver gets a little busy, or its
> connectivity blinks out temporarily, then the whole domain can become
> unresolvable for anyone who doesn't already have the relevant
> information cached. If the domain owner cares about the availability of
> that zone, they should arrange for at least one other nameserver to be
> authoritative for the zone, and then update the delegation records and
> the NS records in the zone to reflect that redundancy.
> 
> - Kevin
> 
>