NSLOOKUP & PING return incorrect IP address on LAN

SBS2008 network. The SBS box is in charge on the LAN, running DHCP & DNS.

The network is 10.0.100.x
Subnet 255.255.255.0

PC1 has dynamic IP 10.0.100.11
PC2 has dynamic IP 10.0.100.15

All PCs and servers on the network resolve PC1 & PC2 to 10.0.100.11

There are no hosts or lmhosts entries
I've stopped DNS & DHCP on the SBS box, cleared the DNS resolver cache, released IPs on the clients, restarted DHCP & DNS and reconnected the clients. Same result.

I'm baffled.

Please unbaffle me.
snooflehammerAsked:
Who is Participating?

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

x
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.

AirShieldCommented:
What are the names of PC1&2??

Just to test, try adding 10.0.100.11 & 10.0.100.15 to dhcp exclusion list, renew the leases and reset the networks adapters. What happens after the test?
snooflehammerAuthor Commented:
PC1 is called CAMERAS
PC2 is called WS10

I excluded the addresses and forced renewal. They both got different IPs. NSLOOKUP still returns the old IP of 10.0.100.11 for both of them.

Server has 30 updates outstanding. Guess I'll apply them...
AirShieldCommented:
where are running nslookup from?? does this behavior happens from every PC?

It sounds like a DNS issue, have you tried rebooting the sever after the test?
CompTIA Security+

Learn the essential functions of CompTIA Security+, which establishes the core knowledge required of any cybersecurity role and leads professionals into intermediate-level cybersecurity jobs.

snooflehammerAuthor Commented:
Every PC on the network. I agree it's DNS-related.

The server is going to reboot once the patches have installed.
AirShieldCommented:
Ok, post back after the reboot.
Cliff GaliherCommented:
Nowhere in your list of things that you did do I see that you removed any DNS records. I'm guessing that if you open the DNS administrative snap-in and view all of the DNS records you will find one that references the PC name you are using and the wrong IP. DHCP will *add* records, but it doesn't delete old ones, and it is legal for one machine to have multiple IP addresses in DNS (for load balancing, round-robin resolution, and other advanced topologies) so that old record can hang out there indefinitely if you don't manually remove it.

Do that, THEN flush the DNS resolver cache, and I think you'll see things start working.

-Cliff

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
ltswebCommented:
Agree with Cliff!  Check DNS and expand the domain and you will likely find both machine names with same IP.  Delete the one that is incorrect, right click on server name in DNS, Scavenge, and Clear Cache.

See: http://blogs.technet.com/b/askpfe/archive/2011/06/03/how-dns-scavenging-and-the-dhcp-lease-duration-relate.aspx  for an explanation.
snooflehammerAuthor Commented:
In all my years of dealing with Windows servers, and it's been a few, I never knew you could do that. Always happy to learn.

Thanks, man
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
Internet Protocols

From novice to tech pro — start learning today.