How to configure the DHCP to make a priority between the subnets inside same shared network

Tim Gavin livewire98801 at
Tue Feb 1 18:11:35 UTC 2011

What's wrong with that, and why would it break?  I would also have a lot 
of use out of a 'priority' block, with a 'backup' block.  In the past, I 
had a block that was too small, with a NAT block to increase the useful 
size until I could get new allocations from ARIN.  Now that I'm done 
with that situation, I would still find a 'backup' block useful, though 
not as much as before.

I never posted a thread about it because I found on in the archives 
saying why it wasn't implemented, but I think it's a valid feature 
request.  As long as addresses are assigned according to RFC in the 
'primary' block, what would it hurt to implement this?  Maybe set a 
longer lease time on the 'primary' block, and a short one on the 
'backup' block.  If a device renews the allocated address before expiry, 
it's renewed, but if that client reconnects after the lease with a 
DISCOVER, it gets allocated an address from the 'primary' block if there 
is one available.  If there isn't a primary address available, it gets 
reallocated the same backup address it had previously.

On 02/01/2011 05:34 AM, Simon Hobson wrote:
> The operation you observe is correct. What you want is not and WILL 
> break sooner or later.

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