Extremly frequent DHCP renews overloads the XG firewall slowing down all traffic.

It seems that the DHCP server configured on the XG125 is renewing DHCP adresses so frequently that it takes all resources on the XG125.  

If I check the logs I have 52 pages of renews of the same IP adress:

 

If I remove the device with the IP the problem is temporary solved. The internet works again and other devices can join the network again. But after a while (2 days) the same thing happens again on a different PC with a different IP adress.

I can see that the XG125 is under much more load than it was initially. I didn't change anything in the configuration. To me it seems like a bug in the DHCP server, does any one else have this kind of problems?

My DHCP settings:

  • Hello, I notice that your default lease time is 1440 minutes (24 hours) and your max lease time is set to 2880 minutes (48 hours)

     

    If you change those to 43200 (30 days) or higher if possible you will not have this issue. 

  • In reply to ZALARID:

    Thanks ZALARID, I have changed it to 43200. Let's wait and see if this works. But isn't it strange that this default settings causes so many problems?

  • In reply to Robin Blaauw:

    In a situation with public access wifi you might want a short lease time. If it is a private network then the lease time can be extended. 

  • In reply to ZALARID:

    Robin Blaauw,

      How many devices are feeding off your DHCP pool? I couldnt imagine this causing a noticeable drain on your network. You say 52 pages of the same IP address, what is the time frame for this? 

  • In reply to ZALARID:

    Currently 13 devices assigned an IP from the DHCP pool. 

    Previously as you can see on the first screenshot in the post the renew on the same IP was 2 times per second. So my 52 pages log is about 1 minute timeframe in total.

     

    Currently the network behaves much better with the renew set to 30 days. But still IP adresses are getting renewed within 15 min, how is this possible?

     

  • In reply to Robin Blaauw:

    This will depend on your device NIC settings, if you have power saving when idle enabled, then when it is no longer idle will request a new address.

    My guess.

    Ian