Let me tell you a story. I am at work. Everything is fine and dandy. Then, to my surprise. Internet stops working. As an aspiring IT guy i think to myself "Yay! now I'm getting payed to fix my computer"
I start troubleshooting. Run an ipconfig. it tells me that my lan ip is 172.15. yadda yadda.
Check the router: Router is giving out 192.168.0.1-90 all other settings are fine. no static ip everything is running DHCP
5 other computers at work with no issues. I say "must be a problem with my computer." so I reformat
Same issue, Same ip.
There is a unused server (power edge) on the network. unplugged it and internet was returned. Yay
Ipconfig: same 172 address yet i have internet.
Call my brother (Actual pro IT guy) tells me that its impossible for your computer to work on a network with an invalid ip and i know how to fix it.
so we run through a few steps flushing my ip and renewing and five or six other things.
Same ip. "you hacked i gotta go"
open coworkers laptop he also has a 172 ip address. he has internet.
Asked my boss if anything on the network can give out IP's (we have a d-link poe/switch and a verint DVR) nothing is giving out ips.
A few days latter the router died and we got a new one. logged on and my computer worked fine. Must have been the router.
Bosses computer now has a 172. ip address.
If i unplug the router form the switch then it fixes the problem however we need the switch plugged in so we can have our ip cameras and printer working
(no the cameras nor the dvr or the secruity system are giving out ip's they were all removed in testing)
Far as I can figure its something to do with the switch.
but its a switch.
Where is the 172 coming from?
Why does every one say this is the oddest thing they have ever heard?
Why did you read this stupid. Broken up story that has no story type bits.
How do I fix'it.
TLDR: I have a 172. ip address being assigned by a ghost device on a DHCP network giving out 192 addresses.
All computers are running Windows 7 or 8.
D-link x-stack model DES-3200-52P