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Hi Simon, thanks for your answer<br>
<br>
this particular scenario is a hotspot in a hotel, so address churning
wont be really an issue since guests come and go ( and in most cases
are hardly seen again for a long time ), so i guess i would let the
lease survive after it has been unused for at least to 24 hours before
wiping it out. The reason we want this behaviour is to minimize
problems with VPN clients due to NATing.<br>
<br>
Is this a parameter that is tunable or is mandated by the RFC ? I could
have a separated daemon do the housekeeping of the leases file on
regular intervals ( using the approach you proposed of creating "fake"
leases for 10.1 addresses ) , in a nutshell it would :<br>
<br>
1) read the leases file<br>
2) create the fake leases for every 10.1 addresses unless a lease for a
specific address is active and newer than 24 hours <br>
3) wipe out any 48.37 lease inactive for more than 24 hours<br>
<br>
I suppose the housekeeping daemon should kill dhcpd before touching the
leases file, or is there a way to manipulate this file while dhcpd is
running ?<br>
<br>
- Enrico<br>
<br>
Simon Hobson wrote:
<blockquote cite="mid:a06240811c4465a0f31a4@simon.thehobsons.co.uk"
type="cite">Enrico Demarin (home) wrote:
<br>
<br>
<blockquote type="cite">I am running a shared network configuration
where i have a pool of public routable addresses and a pool of private
addresses, and I am wondering if it's possible in any way to define the
priority which the dhcp server will use in offering these addresses.
<br>
</blockquote>
<br>
No, by defining a shared network you are explicitly telling the server
that (in the absence of any controls such as client classing) all
defined ranges are equivalent.
<br>
<br>
<blockquote type="cite">Given the configuration below, is it possible
in any way to have the dhcp server assign the addresses from the 48.37
network first and begin assigning the addresses of the 10.1 subnet
last ?
<br>
</blockquote>
<br>
If you stop and think about it, that would only work for a short time
anyway. If you could get the server to use one range first, it would
still go on to use the other range in preference to re-using no longer
leased addresses in your first range - that is a specific requirement
of the RFCs in order to minimise address churn.
<br>
</blockquote>
<br>
<blockquote cite="mid:a06240811c4465a0f31a4@simon.thehobsons.co.uk"
type="cite"><br>
<br>
You can split the usage any way you want provided that you can write an
expression to group your clients into classes - but that would be a
fixed "this client belongs in this range" type of assignment.
<br>
<br>
<br>
There is one way in which you could fudge the system to mostly do what
you want though, but it's not very elegant of clean ! If you wrote a
script to make leases for every 10.1 subnet address then you could have
all those addresses marked as having been previously leased. In that
case, the server would allocate new leases from the other ranges as
long as there were 'never leased' addresses left - after that the
server would reclaim and reuse 10.1 addresses.
<br>
<br>
You then have a problem - what next ? How long do you allow a public
address to be unused before you clean up and delete all record of it's
previous use ? When you've done that, do you force clients to switch
addresses into the public pool ? How do you do that ? Will you do it to
a 'running client' (and thus break all their network connections), or
only if they let their lease expire ?
<br>
<pre wrap="">
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</pre>
</blockquote>
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