DHCP leases out of DHCP server pool range

  • What (probably obvious) am I missing, or mis-understanding, in setting-up/using the DHCP server: it is showing leases that are higher than the upper limit of the address pool, e.g. the range of the address pool is to, but there are a some leases like etc.?

  • LAYER 8 Global Moderator

    Did you create statics for these IPs..  Those would always be outside your pool.  Did you change the pool size, after a client had already gotten a lease?  Once a client gets a lease, he would be able to renew this lease even if its outside your current pool.

  • Hi johnpoz, thanks for the reply. Unfortunately, they aren't likely requesting static IP's, they're mostly wireless clients. The pool size was set months ago, and I think that there are "new" leases that are out of range… but I suppose I can't say that with 100% certainty. What would make the clients safely be required to get a new lease? Restarting the DNS server didn't do it... Rebooting the device?

  • LAYER 8 Global Moderator

    you need to look at your leases. If there are one outside your pool range then delete them.. And then let the client get a new lease.  You sure you don't have another dhcp running that could be handing out these leases?

    Its just not possible for the dhcp server to hand out a lease that is not part of the pool unless you setup a static lease for it, or its renewing a lease that exists.

    You can view all leases listed.. If you not seeing this list then I would say you have another dhcp server running.  If your saying these are wireless - are you running an old wifi router as AP and forgot turn off its lease - or maybe its not actually being an AP and your double natting and your clients are getting a lease from that dhcp server.

    Once a lease has been gotten - it could run like that for years and years..  The client just keeps renewing the lease.  And that lease will be there and can be renewed until its expired and the pool needs to hand that IP to another device because its went through all its available in the pool.  Take a look at your full lease listing and just delete all the leases that are outside your pool.  If client is currently on the network with that lease then the gui will not let you delete it.  You would have to flush your arp table so that pfsense thinks the client is offline and then you could delete the lease.  Or you can just edit the leases file directly or just delete it completely and new one will be created, etc.

  • Rebel Alliance Developer Netgate

    If it's still misbehaving, take screenshots of the DHCP server configuration for that interface and the DHCP leases page and post them here, and search for the addresses in question in the DHCP log under Status > System Logs.

  • Thank you johnpoz and jimp, I think deleting the leases did it. Hadn't realized how long those hang around :-) I'll update as suggested if any more out-of-pool addresses appear. Cheers!

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