Dhclient renewal in 30 seconds



  • Just wondering about this continuous message in my system log:

    Jun 16 16:45:51 dhclient[97127]: bound to [WAN IP] – renewal in 30 seconds.
    Jun 16 16:46:21 dhclient[97127]: DHCPREQUEST on ed0 to 192.168.0.1 port 67
    Jun 16 16:46:21 dhclient[97127]: DHCPACK from 192.168.0.1

    Just had my Linksys AG241 suffer the 10Mb LAN ports issue due to faulty caps so put a pfsense box behind it then replaced the Linksys with a Billion 7100s in half-bridge mode with my NZ ISP Xnet. Connection has been very smooth and noticeably more responsive under load so just noticed these messages in the log when idly flicking through the WebGUI. Was wondering if it's something to worry about? It would seem to be a bit of overkill to request details from DHCP every 30secs, though I know you have to have a fairly short interval with a dynamic public IP in half-bridge mode. Xnet is one of those ISP's with a gateway outside the assigned subnet, could that be putting dhclient in a spin? I'm looking forward to the release of the Draytek Vigor 210 PPPoE to PPPoA bridge to avoid the kludge of using half-bridge mode but would still like to be running in the most efficient manner with my current hardware as well.



  • The lease time is controlled by the dhcp server, not the client. Call your ISP and ask why they have set the lease time to such a short time.



  • Could it also be originating from the Billion though? Or could it only be passing those acks through from the ISP? I found this thread elsewhere that mentions the same behaviour (though that user seems to have other issues as well, my connection runs fine for all intents and purposes).



  • Make a capture/sniff on the DHCP ACK message and check lease time. It should be 1 minute in your case (as the renewal time is usually lease_time/2).

    On the other hand, the IP adress 192.168.0.1 seems not to be a public ISP address. Check your half-modem configuration.


Log in to reply