CISCO1941W-A/K9 can't assign IP address as a DHCP server

r.yumang06 · ‎07-09-2018

Hi all,

I have a problem with my 1941, as it can't assign IP address via DHCP

configurations below

ip dhcp bootp ignore
no ip dhcp conflict logging
ip dhcp excluded-address 58.71.90.1 58.71.90.20
ip dhcp excluded-address 58.71.90.91 58.71.90.254
ip dhcp ping packets 4
ip dhcp ping timeout 4000
!
ip dhcp pool GDCInternet
network 58.71.90.0 255.255.255.0
default-router 58.71.90.1
dns-server 8.8.8.8 58.71.1.38 58.71.2.8
domain-name xxxxxx
lease 0 10

Weird thing is that the router automatically deletes the leased address in the sh ip dhcp binding.

Pool GDCInternet :
Utilization mark (high/low) : 100 / 0
Subnet size (first/next) : 0 / 0
Total addresses : 254
Leased addresses : 1
Pending event : none
1 subnet is currently in the pool :
Current index IP address range Leased addresses
58.71.90.33 58.71.90.1 - 58.71.90.254 1

Pool GDCInternet :
Utilization mark (high/low) : 100 / 0
Subnet size (first/next) : 0 / 0
Total addresses : 254
Leased addresses : 0
Pending event : none
1 subnet is currently in the pool :
Current index IP address range Leased addresses
58.71.90.33 58.71.90.1 - 58.71.90.254 0

I have clear arp, conflicts and binding still the same problem. ( also attached the debug output)

r.yumang06 · ‎07-09-2018

attached another output from debug ip dhcp server packet

fpin211f16Mbpsro01#sh ip dhcp binding
Bindings from all pools not associated with VRF:
IP address Client-ID/ Lease expiration Type
Hardware address/
User name
58.71.90.66 0100.155d.220e.21 Jul 09 2018 07:41 AM Automatic
fpin211f16Mbpsro01#sh ip dhcp binding
Bindings from all pools not associated with VRF:
IP address Client-ID/ Lease expiration Type
Hardware address/
User name
58.71.90.66 0100.155d.220e.21 Jul 09 2018 05:36 PM Automatic
fpin211f16Mbpsro01#sh ip dhcp binding
Bindings from all pools not associated with VRF:
IP address Client-ID/ Lease expiration Type
Hardware address/
User name
fpin211f16Mbpsro01#sh ip dhcp binding
Bindings from all pools not associated with VRF:
IP address Client-ID/ Lease expiration Type
Hardware address/
User name

r.yumang06 · ‎07-09-2018

also tried to manually assign an IP address to some host and this is what I got

IPv4 Address. . . . . . . . . . . : 58.71.90.252(Duplicate)

Subnet Mask . . . . . . . . . . . : 255.255.255.0

IPv4 Address. . . . . . . . . . . : 58.71.90.101(Duplicate)

Subnet Mask . . . . . . . . . . . : 255.255.255.0

IPv4 Address. . . . . . . . . . . : 58.71.90.100(Duplicate)

Subnet Mask . . . . . . . . . . . : 255.255.255.0

tried running IP scanner to check for possible IP conflicts, no issues..