Binding error/bug ?

Bruce Hudson Bruce.Hudson at Dal.Ca
Fri Apr 20 12:29:35 UTC 2007

    Okay, let's see if the first if this makes any more sense with the
first half of the message. Maybe the listserver will like it better this

> According to previous information on the list, IP leases are bound to
> either Client ID and/or MAC. But witch MAC ?
    It uses the MAC address in the request.
> But shouldn't the lease file (DHCPd) bind the IP to the "real Client
> MAC" contained in option 61, not the "Client MAC" that's sending the
> packet to the DHCP server ?
    The correct answer is: neither of the above. The capture you gave
has three "MAC addresses".
  1) > Ethernet II, Src: 00:04:96:10:a6:e0, Dst: 00:11:85:5c:8d:43

  2) > Bootstrap Protocol
     >      Client MAC address: 00:06:0d:4d:c0:be (HP_4d:c0:be)
  3) >      Option 61: Client identifier
     >           Hardware type: Ethernet
     >           Client MAC address: 00:50:b9:80:0e:56 (XitronTe_80:0e:56)
    The first is presumably the address of your relay or the last router in
the path between it and your server. The second is the MAC address that is
associated with the lease. The client identifier, which is a MAC address by
co-incidence (or client choice) is the unique key that will determine what
address you get. It will match client identifiers in your configuration, not
Bruce A. Hudson                         | Bruce.Hudson at Dal.CA
UCIS, Networks and Systems              |
Dalhousie University                    |
Halifax, Nova Scotia, Canada            | (902) 494-3405

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