11-24-2013 04:17 PM - edited 03-04-2019 09:40 PM
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.
Solved! Go to Solution.
11-26-2013 06:22 AM
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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11-24-2013 05:48 PM
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
11-24-2013 11:09 PM
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
11-24-2013 11:55 PM
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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11-25-2013 12:35 AM
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
11-25-2013 05:16 PM
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.
11-25-2013 11:53 PM
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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11-26-2013 02:57 AM
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...
11-26-2013 06:00 AM
@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#
11-26-2013 06:22 AM
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.
11-26-2013 07:09 AM
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
11-26-2013 07:57 AM
@ 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.
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