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Can DHCP cause network anomalies?

Damian Gardner
Damian Gardner asked
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Hello - we are experiencing weird behavior from our Windows Server 2008R2 LAN  - some servers lose access to the Internet but are still accessible to the local network, and at times ALL servers and services drop off the network, but come back in 5-10 minutes time.  So we're wondering if this is somehow caused by DNS or DHCP or possibly a combination of things.  Just starting our investigation and looking for any help we can get.

thanks
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when the devices go offline, can you do a nslookup and see dns is working Ok.
Its not DHCP for sure.
JohnBusiness Consultant (Owner)
Most Valuable Expert 2012
Expert of the Year 2018

Commented:
Also make sure you have fewer devices (by 2 or 3) than your DHCP scope.
Damian GardnerIT Admin

Author

Commented:
Hi John.  I think my device count probably does exceed the DHCP scope, so that's something that might be a problem.  I would assume that the excess devices would simply just not get an IP and not affect the network adversely. Is that not the case?  And for the nslookup, what command could I issue to test the DNS thru nslookup?  anything at all, or something specific?

thanks
JohnBusiness Consultant (Owner)
Most Valuable Expert 2012
Expert of the Year 2018

Commented:
Look in the DHCP lists in the servers. That should tell you.
Business Consultant (Owner)
Most Valuable Expert 2012
Expert of the Year 2018
Commented:
I should also say that the server lists will tell you the names of the computers using the IP addresses. This is useful information.
Natty GregIn Theory (IT)

Commented:
sounds like your having a NIC problem
Damian GardnerIT Admin

Author

Commented:
Miftaul - I just noticed you're saying "It's NOT DHCP for sure?"  So you don't think this is being caused by DHCP at all - but DNS possibly. Do I understand you right?

thanks
Damian GardnerIT Admin

Author

Commented:
the problem seems to have gone away. so I'm going to close this out.  thank you!
JohnBusiness Consultant (Owner)
Most Valuable Expert 2012
Expert of the Year 2018

Commented:
@Damian_Gardner  - Thanks for the update and I was happy to help.