Re: Best way to retrieve DHCP vendor specific options? -Reply

[Somenath Bandyopadhyay <[e-mail]>]

I see a problem with this implementation. 

Let's call the DHCP server which has the required DHCP
options for my DHCP client as DHCP_OPTION server.

Let's consider the case:
----------------------------------
This DHCP_OPTION server has run out of IP addresses..i.e. it
can not allocate any more IP address but its the only DHCP
server which has specific options for my DHCP client.

In this case, DHCP  negotiation is successful with another
DHCP server and my DHCP client obtained an IP address
successfully.

But my DHCP client can no way get those options information
as per the DHCP spec.

( There are many other cases one can describe so that
getting option is not clean or not possible).

Isn't this is limitation of DHCP spec?

Isn't this possible to extend it such a way that:

1. a DHCP server configured for some DHCP options can still
respond to  DHCP clients request of "get parameter list"?

2. <Some more>


        thanks,   som.


>>> Ted Lemon <[e-mail]> 12/19/96 03:14pm >>>

The only time that the client is in a position to choose a server
based on what it offers is when it is in the SELECTING state,
after
having sent out a DHCPDISCOVER message.  After it's got
an address,
it's stuck with what it got unless it gives up the address and
goes
back to the INIT-REBOOT state.

If it is important that a DHCP client receive vendor-specific
options,
then it must request them in the DHCPDISCOVER broadcast,
wait around
for some reasonable period of time collecting DHCPOFFERs,
and take the
offer that most closely matches what it's looking for.  If it
doesn't
get a DHCPOFFER with the appropriate vendor tags, it has a
choice of
either going back to INIT-REBOOT and trying again, or settling
for
what it got.

			       _MelloN_