At this site we installed a new Dell N Series core replacing a bunch of old junk. As I’m doing the new build I moved all the DHCP requests to the core and away from windows which took care of all the DHCP requests. This was on a off day with no one around (Duh replacing the core) and I was not really worried. After about 30 minutes my console is filling up with the below messages.
Note: Yes it’s VLAN1 it predates me and is waaay too messy to remove in a weekend.
Error “No Free IP Address To Offer in pool VLAN1”
*Start freaking out* Did I fill the pool already? How can that be?
show ip dhcp binding
Everything looks fine, and the pool is not even close to full… To the Logs!
I’ve seen this before in Cisco where a device holds onto a DHCP address. You need to track down the MAC and give the device a reboot. After the reboot (of the device) these errors should go away.