Are 120 second DHCP leases on the WAN ok?



  • Hi,

    When looking at a firewall recently I noticed the WAN gateway issuing 120 second DHCP leases.  That means pfSense renews the lease every 60 seconds.  Is the renewal 100% seamless if the same IP is assigned?  I'm trying to figure out if it's something I should spend more time on or if it's ok to ignore.

    TIA,
    Ryan


  • Netgate

    Not a lot you can do about it if that is what your stupid ISP is doing.



  • Nope, the DCHP server is the king in this situation and you won't be able to use an expiring lease any longer than the server allows you to.



  • 120 second lease?  That's going to generate a lot of traffic on the WAN side as all customers will be renewing every minute.  IIRC, the lease time from my ISP is 7 days, though it's been years since I checked.  Hours or days are typical for DHCP leases.



  • @JKnott:

    120 second lease?  That's going to generate a lot of traffic on the WAN side as all customers will be renewing every minute.

    The IPs are from an on-site, ISP controlled device using the 100.64.0.0/10 space.  The pfSense WAN is the only thing pulling an IP from it.  Other customers would have their own device.

    I was mainly wondering if it's something worth pursuing with the ISP since it's unlikely they'll do anything about it.  It would take a lot of effort, so, if there aren't any significant drawbacks on the pfSense side, I'll probably end up ignoring it.


  • Netgate

    If you don't "feel" it, there's not really anything to do.