DHCPDECLINE issues



  • Hi community

    Some of my clients don't accept their reserved IP. Some of them are esp8266 chips with custom firmware, but I had this problem on some other clients too. When I change the static IP to a new (rand()) one, it works and the client accepts the IP. If I put it back, he won't.
    I assume this has something to do with the previous DHCP request (initial, without reservation) and the new one (with reservation), so they collide and create different ARP requests, like:
    https://gtacknowledge.extremenetworks.com/articles/Solution/DHCP-Clients-sending-DHCPDECLINE-packets
    or
    https://learningnetwork.cisco.com/thread/78567

    
    Jul 17 10:14:47	dhcpd		DHCPDISCOVER from 5c:cf:7f:22:d9:03 via hn4
    Jul 17 10:14:47	dhcpd		DHCPOFFER on 172.22.166.31 to 5c:cf:7f:22:d9:03 via hn4
    Jul 17 10:14:47	dhcpd		DHCPREQUEST for 172.22.166.31 (172.22.166.1) from 5c:cf:7f:22:d9:03 via hn4
    Jul 17 10:14:47	dhcpd		DHCPACK on 172.22.166.31 to 5c:cf:7f:22:d9:03 via hn4
    Jul 17 10:14:47	dhcpd		DHCPDECLINE of 172.22.166.31 from 5c:cf:7f:22:d9:03 via hn4: not found
    Jul 17 10:14:51	dhcpd		DHCPDISCOVER from 5c:cf:7f:23:74:3f via hn4
    Jul 17 10:14:51	dhcpd		DHCPOFFER on 172.22.166.32 to 5c:cf:7f:23:74:3f via hn4
    Jul 17 10:14:51	dhcpd		DHCPREQUEST for 172.22.166.32 (172.22.166.1) from 5c:cf:7f:23:74:3f via hn4
    Jul 17 10:14:51	dhcpd		DHCPACK on 172.22.166.32 to 5c:cf:7f:23:74:3f via hn4
    Jul 17 10:14:51	dhcpd		DHCPDECLINE of 172.22.166.32 from 5c:cf:7f:23:74:3f via hn4: not found
    Jul 17 10:14:57	dhcpd		DHCPDISCOVER from 5c:cf:7f:22:d9:03 via hn4
    Jul 17 10:14:57	dhcpd		DHCPOFFER on 172.22.166.31 to 5c:cf:7f:22:d9:03 via hn4
    Jul 17 10:14:57	dhcpd		DHCPREQUEST for 172.22.166.31 (172.22.166.1) from 5c:cf:7f:22:d9:03 via hn4
    Jul 17 10:14:57	dhcpd		DHCPACK on 172.22.166.31 to 5c:cf:7f:22:d9:03 via hn4
    Jul 17 10:14:57	dhcpd		DHCPDECLINE of 172.22.166.31 from 5c:cf:7f:22:d9:03 via hn4: not found
    Jul 17 10:15:02	dhcpd		DHCPDISCOVER from 5c:cf:7f:23:74:3f via hn4
    Jul 17 10:15:02	dhcpd		DHCPOFFER on 172.22.166.32 to 5c:cf:7f:23:74:3f via hn4
    Jul 17 10:15:02	dhcpd		DHCPREQUEST for 172.22.166.32 (172.22.166.1) from 5c:cf:7f:23:74:3f via hn4
    Jul 17 10:15:02	dhcpd		DHCPACK on 172.22.166.32 to 5c:cf:7f:23:74:3f via hn4
    Jul 17 10:15:02	dhcpd		DHCPDECLINE of 172.22.166.32 from 5c:cf:7f:23:74:3f via hn4: not found
    Jul 17 10:15:03	dhcpd		DHCPDISCOVER from a0:20:a6:1a:00:8d via hn4
    Jul 17 10:15:03	dhcpd		DHCPOFFER on 172.22.166.41 to a0:20:a6:1a:00:8d via hn4
    Jul 17 10:15:03	dhcpd		DHCPREQUEST for 172.22.166.41 (172.22.166.1) from a0:20:a6:1a:00:8d via hn4
    Jul 17 10:15:03	dhcpd		DHCPACK on 172.22.166.41 to a0:20:a6:1a:00:8d via hn4
    Jul 17 10:15:03	dhcpd		DHCPDECLINE of 172.22.166.41 from a0:20:a6:1a:00:8d via hn4: not found
    

    I've deleted the static addresses and it seems like they are getting "known hosts" addresses, because one has .120, the others .125 and 126.

    Any ideas?

    Thanks!

    Noc.

    PS: could also be the solution to this old post: https://forum.pfsense.org/index.php?topic=54220.0



  • Any ideas?

    Get better clients.  ;)

    What happens if you don't reserve an address?  Do they then accept an address within the pool?



  • yes, works. Only reservation not. If I add a new reserved IP, it works fore some hours.

    (When you want to have home automation with MQTT broker, you want to use those chips ;) )



  • @Noctis:

    yes, works. Only reservation not. If I add a new reserved IP, it works fore some hours.

    (When you want to have home automation with MQTT broker, you want to use those chips ;) )

    Well, perhaps you should be looking at why those clients are declining an address they requested.  I have several devices with reserved IPs and they all work fine.  However, just to prove whether it's the client of pfSense, try the same with a cheap router.  If it still fails then the problem is with the client.



  • Can you be more specific about what wireless infrastructure you are using with the ESP8266 chips?
    Make sure that the stateful firewall in the wireless infrastructure is turned off.  I have seen issues where the wireless infrastructure's firewall doesn't track the states of a reserved DHCP address very well.



  • I'm using an Meraki (Cisco) MR33 AP. Atm, I'm trying to install a different one to sort things out.