Cisco 1811W router, IOS 15.1(4)M6, DHCP server not working on internal VLAN but configuration looks OK to me.
C1811W#sh run int vl252
!
interface Vlan252
ip address 192.168.252.252 255.255.255.0
ip nat inside
ip virtual-reassembly
!
C1811W#sh run | section dhcp pool
ip dhcp pool VLAN252
network 192.168.252.0 255.255.255.0
subnet prefix-length 24
dns-server 192.168.252.252
default-router 192.168.252.252
C1811W#sh ip dhcp pool
Pool VLAN252 :
Utilization mark (high/low) : 100 / 0
Subnet size (first/next) : 0 / 0
Total addresses : 256
Leased addresses : 0
Pending event : none
1 subnet is currently in the pool :
Current index IP address range Leased addresses
192.168.252.0 192.168.252.0 - 192.168.252.255 0
C1811W#debug ip dhcp server event
DHCP server event debugging is on.
*Mar 20 15:46:23.437: DHCPD: Sending notification of DISCOVER:
*Mar 20 15:46:23.437: DHCPD: htype 1 chaddr 0019.9d07.e0d0
*Mar 20 15:46:23.437: DHCPD: remote id 020a0000c0a8fcfc040000fc
*Mar 20 15:46:23.437: DHCPD: circuit id 00000000
*Mar 20 15:46:23.437: DHCPD: Seeing if there is an internally specified pool class:
*Mar 20 15:46:23.437: DHCPD: htype 1 chaddr 0019.9d07.e0d0
*Mar 20 15:46:23.437: DHCPD: remote id 020a0000c0a8fcfc040000fc
*Mar 20 15:46:23.437: DHCPD: circuit id 00000000
*Mar 20 15:46:23.441: DHCPD: there is no address pool for 192.168.252.252.
