DNS search order not working

we have four DNS servers.

nsnt4.cissltd.com is on a separate ISP than the first three.  Yesterday we shut off the nsnt2.cissltd.com and nsnt3.cissltd.com servers to rebuild a failed raid array.  when the servers were off our DNS lookups failed and all of web hosting services were unavailable.  Not good.  Can anyone provide an answer as to why our DNS search order isn't working?

nsnt2.cissltd.com is the primary DNS server, the other DNS servers are all secondary.
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

* check of update the ROOT hints
* Check your forwarders configured on the DNS servers

bensonwalkerAuthor Commented:
thanks for the response.

there are a bunch of entries in the "root hints" - none of them recognizable to me: a, b, c, ....m.root-servers.net    all with some pretty "flakey" looking IP address.... is one of them........

we don't have any forwarders defined.....should we have the other local DNS servers defined in the forwarders?
You can try that as a dirty walkaround. Till the other servers are back up again
Big Business Goals? Which KPIs Will Help You

The most successful MSPs rely on metrics – known as key performance indicators (KPIs) – for making informed decisions that help their businesses thrive, rather than just survive. This eBook provides an overview of the most important KPIs used by top MSPs.

bensonwalkerAuthor Commented:
got the nsnt4.cissltd.com back...it was registered with network solutions as .98 and needed to be .100 ...this change has brought this service back online.

looks like the root-hints servers that are in the DNS settings we have are all owned by Network Solutions/Arin

Although the problem seems to be resolved, you may want to be clear on what problem you were really having.

Based on what I understand the root hints would not be involved here.

It sounds like you were having problems with the servers that hold the zone files for your domain.  That is if I wanted to access a host in your domain, I would end up querying them to find the name.  If that is true, then your DNS servers knowing about the root-hints have nothing to do with me looking up hosts in your domain.

me <-> my dns server <-> my isp's forwarders or root hints zone <-> your authoritative dns servers  for your domain

It sounds like your authoritative DNS servers for your domain were where the problem was.  Is that so?

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
bensonwalkerAuthor Commented:
that sounds correct.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.