A DHCP question from a PhD student...

[Yaron Weinsberg]

Hi There,

I hope you can help me out  here with the following question:
(I am a PhD student who teaches DHCP among other things)

what is the purpose the transaction id in the DHCP packets?
the rfc say that it is used to correlate requests and replies but the client
can ALWAYS check the "chaddr" (client hardware address) to verify that
the reply is for him.  Even if a client sets the broadcast bit, the chaddr will
always contain the target mac address...

also, if multiple responses are received with the same MAC (due to the
UDP nature of the protocol - and relay agents) - still the dhcp client
always knows the state of the protocol. If an IP has already been
assigned it can ignore messages etc..

do I miss something here ?

thanks for your help,

 -  Yaron.