My dhcp keeps shutting down

I have read a few posts about SBS dhcp shutting down. I don’t know if it is just SBS or not but I do know that SBS will shut down it’s dhcp service if it sees another dhcp server. I usually do two nic servers with the isp connected to the second nic. I do not recall ever seeing the dhcp server shut down with this config. I did see dhcp shut down at one account. Troubleshooting 101. Turn off all the workstations. It still shut down. Unplug everything from the switch except the sever. I started the dhcp and it stayed running. I start plugging in things and I see the service shut down. Curse the cable person who did not leave a drawing with cable jacks. Double curse the cable tech who comes back after I spent an hour making a drawing and he takes my drawing. Stupid me for not making copies, pdfs and stapling it to the wall. Back to the story. A cheap print sharing device has a dhcp service built in to it. Why? Who knows. I disabled it and all was well. Except the stupid thing reenabled itself. Toss that device out the window.

So I see people post in the SBS newsgroup about this dhcp issue.  Someone said unbind the dhcp from the external nic. Sounds easy enough. I keep that thought in mind for later use. Finally I see someone post and I respond with my ISP to external nic, internal to network switch. He unplugged all the devices from the switch except the SBS. He still has the same problem. So I mention the unbind dhcp from the external nic. He posts back “How do you do that?” Fair question so I try it myself. Darned it I see it so I keep looking. 

Go to your DHCP manager. Right click on your server name/properties/advanced/bindings. Make sure your only your internal
nic is checked.Try to restart dhcp after you unbind from external nic.


2 thoughts on “My dhcp keeps shutting down

  1. Nice post Jim.  Out of curosity, was the print server in question an Intel? 😉  

    No, it was a  Hawking HPS1P. That device has worked pretty goo at a few installs.


  2. hi, thanks. gave me a clue to solve another issue i had with a redeployed server (bare metal). The DNS service would not start. DNS entries were missing. Basically no network. Apparently NICs had older BINDS causing confusion within the server. After reading this post, it gave me an idea – by using the DHCP’s DNS dynamic updates option i was able to trigger the DNS service to restart properly. Thanks, Tim.

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