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 From:  Fred Wright <fw at well dot com>
 To:  m0n0wall at lists dot m0n0 dot ch
 Subject:  Re: [m0n0wall] DHCP server - static clients only
 Date:  Thu, 24 Jun 2004 11:54:34 -0700 (PDT)
On Thu, 24 Jun 2004, Adam Nellemann wrote:
> I'm not quite following the other discussion in this thread. What is 
> the need for a lease/mapping that survives a reboot (or more 
> correctly, a crash)? And isn't this what the static mappings are for 
> (they should certainly survive any kind of crash, altough the lease 
> would still have to be renewed I guess, but again I don't see the harm 
> in that?)

It insures that existing access isn't killed by the loss of the lease.  
Without persistent mappings, the reincarnated server may reassign an
address to a different client, resulting in two clients with the same

Sure you can get around this with static mappings, but if you need to make
all mappings static to make them reliable, then what good are dynamic
mappings?  The intent is that you should only need static mappings for
machines that need to be accessed as servers (and hence at known IP
addresses).  Of course for maximum reliability you shouldn't use DHCP for
servers at all, but sometimes the convenience of managing addresses
centrally outweighs the reliability issue.

					Fred Wright