DHCP problem

Unanswered Question
Dec 12th, 2007
User Badges:

hi all,

I am configuring a catalyst 4507 switch as DHCP server , it was working fine but suddenly it stopped distributing dhcp in some pools and still working in others !!

i used clear ip dhcp binding , ireloaded the switch and still having same problem .

using debug ip dhcp server events it gives the following

006853: *Dec 11 14:13:41.859: DHCPD: address pool xyz is empty


interface vlan 128

ip address

ip dhcp pool xyz



inter gig7/14

switchport mode access

switchport access vlan 128

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Kevin Dorrell Wed, 12/12/2007 - 04:55
User Badges:
  • Green, 3000 points or more

Is it possible that all the potential DHCP addresses in the pool are active, even though they are not in the bindings table? When you reboot the switch it will lose its bindings table, unless you keep it on a server as well. But there might still be clients out there that still believe they have a valid lease. So, before the DHCP server allocates an IP address, it will ping it first to make sure it is not accidentally in use already. Could it be it got a ping back for every address in the range?

(Clutching at straws here, but its the best I can think of.)

Kevin Dorrell


mostafaammar Wed, 12/12/2007 - 05:36
User Badges:

Dear Kevin ,

i tried the command

ip dhcp ping packets 0

to disable pinging but i have the same problem .

also when applying clear ip dhcp binding * , no ips return to the pool , and also the number of pcs in the vlan does not exeed 50 devices .


This Discussion