Solved: DHCP binding from pool fails

Pderby · ‎11-24-2013

I have a device with embedded Microchip Technology, Inc. ethernet network hardware. When the device issues a DHCP request my CISCO 1921 router shows this binding:

10.6.18.64 0004.a3b7.8c49 Nov 25 2013 06:50 PM Automatic

So I clear the binding and define a pool to force assignment to 10.6.18.44 I've tried two versions of defining the pool and both fail:

ip dhcp pool caotag

host 10.6.18.44 255.255.255.0

hardware-address 0004.a3b7.8c49

client-name caotag

Here is the DHCP debug:

000206: Nov 24 18:34:44.529 EST: DHCPD: removing ARP entry (10.6.18.62 vrf default).

000207: Nov 24 18:36:14.052 EST: DHCPD: client's VPN is .

000208: Nov 24 18:36:14.052 EST: DHCPD: No option 125

000209: Nov 24 18:36:14.052 EST: DHCPD: DHCPDISCOVER received from client 0004.a3b7.8c49 on interface BVI1.

000210: Nov 24 18:36:14.052 EST: DHCPD: Allocate an address without class information (10.6.18.0)

000211: Nov 24 18:36:14.052 EST: DHCPD: Saving workspace (ID=0xA000001D)

000212: Nov 24 18:36:16.052 EST: DHCPD: Reprocessing saved workspace (ID=0xA000001D)

000213: Nov 24 18:36:16.052 EST: DHCPD: DHCPDISCOVER received from client 0004.a3b7.8c49 on interface BVI1.

000214: Nov 24 18:36:16.052 EST: DHCPD: Sending DHCPOFFER to client 0004.a3b7.8c49 (10.6.18.63).

000215: Nov 24 18:36:16.052 EST: DHCPD: no option 125

000216: Nov 24 18:36:16.052 EST: DHCPD: broadcasting BOOTREPLY to client 0004.a3b7.8c49.

000217: Nov 24 18:36:16.060 EST: DHCPD: client's VPN is .

000218: Nov 24 18:36:16.060 EST: DHCPD: No option 125

000219: Nov 24 18:36:16.060 EST: DHCPD: DHCPREQUEST received from client 0004.a3b7.8c49.

000220: Nov 24 18:36:16.060 EST: DHCPD: Can't find any hostname to update

000221: Nov 24 18:36:16.060 EST: DHCPD: Sending DHCPACK to client 0004.a3b7.8c49 (10.6.18.63).

000222: Nov 24 18:36:16.060 EST: DHCPD: no option 125

000223: Nov 24 18:36:16.060 EST: DHCPD: broadcasting BOOTREPLY to client 0004.a3b7.8c49.

Clearing the binding and assigning this pool definition doesn't work either:

no ip dhcp pool caotag

ip dhcp pool caotag

host 10.6.18.44 255.255.255.0

client-identifier 0100.04a3.b78c.49

client-name caotag

Debug output for the second attempt:

cisco1921#debug ip dhcp server packet

DHCP server packet debugging is on.

cisco1921#

000225: Nov 24 18:50:23.366 EST: DHCPD: client's VPN is .

000226: Nov 24 18:50:23.366 EST: DHCPD: No option 125

000227: Nov 24 18:50:23.366 EST: DHCPD: DHCPDISCOVER received from client 0004.a3b7.8c49 on interface BVI1.

000228: Nov 24 18:50:23.366 EST: DHCPD: Allocate an address without class information (10.6.18.0)

000229: Nov 24 18:50:23.370 EST: DHCPD: Saving workspace (ID=0x7C00001E)

000230: Nov 24 18:50:25.366 EST: DHCPD: Reprocessing saved workspace (ID=0x7C00001E)

000231: Nov 24 18:50:25.366 EST: DHCPD: DHCPDISCOVER received from client 0004.a3b7.8c49 on interface BVI1.

000232: Nov 24 18:50:25.366 EST: DHCPD: Sending DHCPOFFER to client 0004.a3b7.8c49 (10.6.18.64).

000233: Nov 24 18:50:25.366 EST: DHCPD: no option 125

000234: Nov 24 18:50:25.366 EST: DHCPD: broadcasting BOOTREPLY to client 0004.a3b7.8c49.

000235: Nov 24 18:50:25.374 EST: DHCPD: client's VPN is .

000236: Nov 24 18:50:25.374 EST: DHCPD: No option 125

000237: Nov 24 18:50:25.374 EST: DHCPD: DHCPREQUEST received from client 0004.a3b7.8c49.

000238: Nov 24 18:50:25.374 EST: DHCPD: Can't find any hostname to update

000239: Nov 24 18:50:25.374 EST: DHCPD: Sending DHCPACK to client 0004.a3b7.8c49 (10.6.18.64).

000240: Nov 24 18:50:25.374 EST: DHCPD: no option 125

000241: Nov 24 18:50:25.374 EST: DHCPD: broadcasting BOOTREPLY to client 0004.a3b7.8c49.

cisco1921#

cisco1921#no debug ip dhcp server packet

I did some searching and found reference to the "No optin 125" error message. All devices are on one network 10.6.18.0 255.255.255.0

I've stared at this for hours. Anyone run into this problem? I'm probably missing something obvious.

cadet alain · ‎11-26-2013

Hi,

the .44 is in the binding database with client-identifier of 01xxx so clear it : clear ip dhcp binding 10.6.18.44

clear ip dhcp binding 10.6.18.64 too

get rid of the pool(no ip dhcp pool caotag),recreate the pool as such:

ip dhcp pool caotag

host 10.6.18.44 255.255.255.0

hardware-address 0004.a3b7.8c49

client-name caotag

then release/renew on the client and it should be working.

Regards

Alain

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View solution in original post

Gabriel Hill · ‎11-24-2013

Hello Paul,

Your configuration looks correct to me. Have you used the: "ip dhcp excluded-address" command as well? Not that it should matter, but it may be worth trying. I assume you have checked to be sure .44 is not being used currently?

What IOS version are you running?

-G

Rolf Fischer · ‎11-24-2013

Hi Paul,

this looks interesting:

DHCPD: Sending DHCPOFFER to client 0004.a3b7.8c49 (10.6.18.64)

Normally we would expect Hareware Type 01 (Ethernet) and that's what you used to form the client-identifier in the host pool.

Have you tried to prepend a "00" instead of the "01"? I never saw this so far, but it's worth a try I guess.

HTH

Rolf

cadet alain · ‎11-24-2013

Hi Rolf,

This is a perfectly valid MAC address and the sh dhcp binding clearly shows that this is the MAC address that is used a a client-id here.What is puzzling me though is that we have the same debug output when using the client-identifier prefixed with 01 in the pool definition.

I'd also like to know what is not working because the Discover-Offer-Request-Ack process is successful in each case so the client should get the IP.

Regards

Alain

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Rolf Fischer · ‎11-25-2013

Hi Alain,

you're right - I guess I had my eyes only half-opened this morning (thought the debug showed 0000.04a3.b78c.49).

So please ignore my first posting.

Best regards

Rolf

Pderby · ‎11-25-2013

The device that is getting an IP address assigned, but not the address from the pool, is connected to a GIG-E interface on a 3750 switch running IOS 15.0(2)SE2. The switch is connected to a 1921 Router. The DHCP addresses are issued by the router for the entire subnet.

I moved the device with the embedded ethernet over to an interface on the Router to eliminate the switch. No difference. The device still gets an IP address, just not the one from the pool.

cadet alain · ‎11-25-2013

Hi,

Can you post output from sh ip dhcp conflict and sh ip dhcp binding as well as sh run | i ip dhcp

Regards

Alain

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Alexandr Alakin · ‎11-26-2013

Hi, Paul,

Did you try to use client-identifier option?

ip dhcp pool CAOTAG

host 10.6.18.44 255.255.255.0

client-identifier 0100.04a3.b78c.49

It definitely was working fine for different clients: Windows XP, Windows 7, Android.

DHCP Static Binding on Cisco IOS.

Ooops...

HTH Alexandr

Pderby · ‎11-26-2013

@Alexandr - the client-identifier option was the second setting I tried. It is the second example in my original post.

@alain - here's the output from the commands you requested I run:

cisco1921#sh ip dhcp conflict

IP address Detection method Detection time VRF

10.6.18.104 Ping Nov 09 2013 12:08 PM

cisco1921#

cisco1921#show ip dhcp binding

Bindings from all pools not associated with VRF:

IP address Client-ID/ Lease expiration Type

Hardware address/

User name

10.6.18.8 01dc.9fdb.b400.8d Infinite Manual

10.6.18.20 0001.e630.f98b Infinite Manual

10.6.18.21 01f4.ce46.367b.3e Infinite Manual

10.6.18.24 0158.9396.1926.90 Infinite Manual

10.6.18.26 0100.0e8f.8257.a3 Infinite Manual

10.6.18.30 0114.109f.e62f.4b Infinite Manual

10.6.18.31 0110.ddb1.98c0.1e Infinite Manual

10.6.18.33 0190.2b34.3fa4.4f Infinite Manual

10.6.18.34 01d4.9a20.5883.94 Infinite Manual

10.6.18.35 01d4.9a20.d08c.4a Infinite Manual

10.6.18.36 0100.1f3a.56ec.ac Infinite Manual

10.6.18.37 0100.1c23.fddc.ea Infinite Manual

10.6.18.38 0170.73cb.f1d6.f5 Infinite Manual

10.6.18.39 0170.73cb.f1d6.f4 Infinite Manual

10.6.18.40 0025.2f21.8302 Infinite Manual

10.6.18.42 0100.408c.dc43.7c Infinite Manual

10.6.18.43 0100.408c.7102.15 Infinite Manual

10.6.18.44 0100.04a3.b78c.49 Infinite Manual

10.6.18.50 0100.c0b7.b422.c7 Infinite Manual

10.6.18.51 0100.c0b7.d713.a0 Infinite Manual

10.6.18.60 0018.610b.8ebd Infinite Manual

10.6.18.64 0004.a3b7.8c49 Nov 26 2013 08:04 PM Automatic

10.6.18.65 0124.7703.281c.28 Nov 26 2013 09:58 PM Automatic

10.6.18.66 0160.6720.00ed.10 Nov 27 2013 01:13 AM Automatic

10.6.18.70 0100.1dc9.d0a4.68 Infinite Manual

10.6.18.80 0100.0678.1811.b9 Infinite Manual

10.6.18.81 0100.0678.1812.53 Infinite Manual

10.6.18.83 0110.40f3.f02a.d3 Infinite Manual

10.6.18.86 0100.0420.05c1.94 Infinite Manual

10.6.18.87 0100.0420.0696.f7 Infinite Manual

10.6.18.88 0100.0420.05c1.93 Infinite Manual

10.6.18.89 0100.0420.05bc.a7 Infinite Manual

10.6.18.90 0100.2308.6c97.e4 Infinite Manual

10.6.18.91 0100.e091.98e7.46 Infinite Manual

10.6.18.100 0154.2696.168b.36 Infinite Manual

10.6.18.101 0178.6c1c.a66f.bc Infinite Manual

10.6.18.102 0110.40f3.d1e3.ab Infinite Manual

10.6.18.103 0140.3004.8f72.82 Infinite Manual

cisco1921#sh run | i ip dhcp

no ip dhcp use vrf connected

ip dhcp excluded-address 10.6.18.1 10.6.18.8

ip dhcp excluded-address 10.6.18.10 10.6.18.19

ip dhcp pool dhcppool

ip dhcp pool vera3

ip dhcp pool ruckus

ip dhcp pool vostro

ip dhcp pool vostroenet

ip dhcp pool appletve

ip dhcp pool appletvw

ip dhcp pool apc2

ip dhcp pool apc1

ip dhcp pool lg

ip dhcp pool lge

ip dhcp pool iphonetj

ip dhcp pool macbookenet

ip dhcp pool macbookpro

ip dhcp pool iphonepld

ip dhcp pool marantzmbr

ip dhcp pool marantzden

ip dhcp pool sqoffice

ip dhcp pool sqden

ip dhcp pool sqliving

ip dhcp pool sqbedroom

ip dhcp pool ipdadtj

ip dhcp pool imac

ip dhcp pool imacenet

ip dhcp pool laserjetlower

ip dhcp pool ipadpld

ip dhcp pool laserjetupper

ip dhcp pool ted

ip dhcp pool tjpc

ip dhcp pool appletvden

ip dhcp pool ubiquiti

ip dhcp pool ooma

ip dhcp pool axis1033w

ip dhcp pool axis207w

ip dhcp pool caotag

ip dhcp pool aria

cisco1921#

cadet alain · ‎11-26-2013

Hi,

the .44 is in the binding database with client-identifier of 01xxx so clear it : clear ip dhcp binding 10.6.18.44

clear ip dhcp binding 10.6.18.64 too

get rid of the pool(no ip dhcp pool caotag),recreate the pool as such:

ip dhcp pool caotag

host 10.6.18.44 255.255.255.0

hardware-address 0004.a3b7.8c49

client-name caotag

then release/renew on the client and it should be working.

Regards

Alain

Don't forget to rate helpful posts.

Alexandr Alakin · ‎11-26-2013

I would try to use your 3750 as DHCP-server (to check if behaviour is exactly the same with 1921's behaviour or not). I presume some other devices receive pseudo-dynamic IP addresses correctly and problem only with this one, right?

Alexandr

HTH Alexandr

Pderby · ‎11-26-2013

@ Alexandr: yes the other 50 or so devices, some with client-identifier and others with hardware-address all receive IP addresses correctly from their pools. Only this one instance didn't initially work. Now all seems to be working fine. I have no idea what caused the hiccup for this one device for the assignment.