ah...chaddr was the field I was looking for. Here is what I think happens based on my experiences:
- Client sends DHCP request with the client-id not present (like the case of my linux machines and the fedora linux box in the example) - IOS router has the DHCP pool defined for the box to assign it an IP. It has "hardware-addess" configured with the hosts mac address - Since client-id is not present, IOS compares the chaddr field with the hardware-address field configured and if it matches, hands out the address I have not done extensive testing on this, but like I said, I have several non windows clients that receive IP addresses through IOS DHCP whereby the pool is configured with "hardware-address". The client is NOT using BOOTP. So...there is my explanation. On Tue, Apr 17, 2012 at 1:54 PM, Joe Astorino <[email protected]>wrote: > I have systems in production environment using DHCP client that get static > addresses via "hardware-address" in the IOS dhcp server configuration. My > takeaway from the articles I have read was that if the client-identifier is > not included, like on that Fedora box the hardware-address was used and > compared with the mac address sent in the client request (not sure what > field this is for sure without looking) > > Regardless of documentation on Cisco.com, like I said I have real working > hosts in this environment so I can tell you first hand it does work. > > On Tue, Apr 17, 2012 at 2:11 AM, Eugene Pefti <[email protected]>wrote: > >> Apparently, a fair amount of what we learn here is what doesn't work >> contrary to the official documentation. I'm still inclined to think that >> this is an expected behaviour as you confirmed it with your two DHCP >> clients and it's natural for them to send option 61. Hence when you have >> "hardware-address" configured under the DHCP pool manual binding doesn't >> work because the DHCP request does contain this client identifier and it >> conflicts with "hardware-address" option >> >> Eugene >> >> From: Kingsley Charles <[email protected]> >> Date: Tue, 17 Apr 2012 10:28:28 +0530 >> To: Eugene Pefti <[email protected]> >> Cc: "[email protected]" < >> [email protected]> >> Subject: Re: [OSL | CCIE_Security] DHCP address assignment using >> hardware address >> >> When I use Windows or IOS router as DHCP client and use "hardware >> address" in the manual binding, it doesn't work. Both of them send DHCP >> request with option 61. >> >> With regards >> Kings >> >> On Tue, Apr 17, 2012 at 6:33 AM, Eugene Pefti <[email protected]>wrote: >> >>> I’m confused by your question, Kings,**** >>> >>> The same guide says that to configure “manual bindings” one must enter >>> “client-identifier” command. What made you think that the >>> “hardware-address” option didn’t work?**** >>> >>> Were you able to simulate BOOTP instead of DHCP request with option 61 ? >>> **** >>> >>> ** ** >>> >>> Eugene**** >>> >>> ** ** >>> >>> *From:* [email protected] [mailto: >>> [email protected]] *On Behalf Of *Kingsley >>> Charles >>> *Sent:* 15 April 2012 09:08 >>> *To:* [email protected] >>> *Subject:* [OSL | CCIE_Security] DHCP address assignment using hardware >>> address**** >>> >>> ** ** >>> >>> Hi all >>> Hi all >>> >>> If I want to configure manual binding that doesn't working with hardware >>> address. Instead, if I specify the client identifies, it works. >>> >>> ip dhcp pool cat >>> host 10.20.30.40 255.255.255.0 >>> hardware-address 0001.0002.0003 >>> >>> >>> The snippet below, claims that hardware address can be used with bootp >>> requests only. Logically, I feel that should be the case because bootp >>> request doesn't have options field. In the case of DHCP request, the option >>> 61 is used to carry client identifier. Hence, it seems, the IOS expect >>> client identifies to be configured, if it a dhcp request. >>> >>> Comments please. >>> >>> >>> Snippet from >>> http://www.cisco.com/en/US/docs/ios/12_2/ip/configuration/guide/1cfdhcp.html#wp1001108 >>> **** >>> >>> Router(dhcp-config)# *client-identifier **unique-identifier ***** >>> >>> Specifies the unique identifier for DHCP clients. This command is used >>> for DHCP requests. >>> >>> Router(dhcp-config)#* hardware-address **hardware-address****type ** >>> >>> *(Optional) Specifies a hardware address for the client. This command >>> is used for BOOTP requests. >>> >>> With regards >>> Kings**** >>> >> >> >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> >> Are you a CCNP or CCIE and looking for a job? Check out >> www.PlatinumPlacement.com >> > > > > -- > Regards, > > Joe Astorino > CCIE #24347 > http://astorinonetworks.com > > "He not busy being born is busy dying" - Dylan > > -- Regards, Joe Astorino CCIE #24347 http://astorinonetworks.com "He not busy being born is busy dying" - Dylan
_______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com
