Client can't keep DHCP lease?



  • I have pfSense wired to my wifi router acting as an access point which is configured to point to pfSense for DHCP. All other clients on my network including my laptop connect fine but my Android phone (Nexus 5X 7.1.2) will only connect for a second or two after obtaining an IP, then disconnect, and go back and forth like that. I don't think it's the phone because it only started happening after using pfSense and it doesn't happen if I let the wifi AP be the DHCP server. Here's what the DHCP logs look like:

    Time Process PID Message
    Jul 10 16:58:48 dhcpd DHCPREQUEST for 172.168.1.100 (172.168.1.1) from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 16:58:48 dhcpd DHCPACK on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 16:59:32 dhcpd reuse_lease: lease age 985 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 16:59:32 dhcpd DHCPDISCOVER from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 16:59:32 dhcpd DHCPOFFER on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 16:59:32 dhcpd reuse_lease: lease age 985 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 16:59:32 dhcpd DHCPREQUEST for 172.168.1.100 (172.168.1.1) from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 16:59:32 dhcpd DHCPACK on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:00:08 dhcpd reuse_lease: lease age 1021 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:00:08 dhcpd DHCPDISCOVER from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:00:08 dhcpd DHCPOFFER on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:00:08 dhcpd reuse_lease: lease age 1021 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:00:08 dhcpd DHCPREQUEST for 172.168.1.100 (172.168.1.1) from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:00:08 dhcpd DHCPACK on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:03:06 dhcpd reuse_lease: lease age 1199 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:03:06 dhcpd DHCPDISCOVER from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:03:07 dhcpd DHCPOFFER on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:03:07 dhcpd reuse_lease: lease age 1200 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:03:07 dhcpd DHCPREQUEST for 172.168.1.100 (172.168.1.1) from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:03:07 dhcpd DHCPACK on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:03:34 dhcpd reuse_lease: lease age 1227 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:03:34 dhcpd DHCPDISCOVER from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:03:34 dhcpd DHCPOFFER on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:03:34 dhcpd reuse_lease: lease age 1227 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:03:34 dhcpd DHCPREQUEST for 172.168.1.100 (172.168.1.1) from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:03:34 dhcpd DHCPACK on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:04:07 dhcpd reuse_lease: lease age 1260 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:04:07 dhcpd DHCPDISCOVER from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:04:07 dhcpd DHCPOFFER on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:04:07 dhcpd reuse_lease: lease age 1260 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:04:07 dhcpd DHCPREQUEST for 172.168.1.100 (172.168.1.1) from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:04:07 dhcpd DHCPACK on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:04:42 dhcpd reuse_lease: lease age 1295 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:04:42 dhcpd DHCPDISCOVER from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:04:42 dhcpd DHCPOFFER on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:04:42 dhcpd reuse_lease: lease age 1295 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:04:42 dhcpd DHCPREQUEST for 172.168.1.100 (172.168.1.1) from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:04:42 dhcpd DHCPACK on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:05:47 dhcpd reuse_lease: lease age 1360 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:05:47 dhcpd DHCPDISCOVER from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:05:48 dhcpd DHCPOFFER on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:05:48 dhcpd reuse_lease: lease age 1361 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:05:48 dhcpd DHCPREQUEST for 172.168.1.100 (172.168.1.1) from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:05:48 dhcpd DHCPACK on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:06:21 dhcpd reuse_lease: lease age 1394 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:06:21 dhcpd DHCPDISCOVER from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:06:21 dhcpd DHCPOFFER on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:06:21 dhcpd reuse_lease: lease age 1394 (secs) under 25% threshold, reply with unaltered, existing lease for 172.168.1.100
    Jul 10 17:06:21 dhcpd DHCPREQUEST for 172.168.1.100 (172.168.1.1) from 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300
    Jul 10 17:06:21 dhcpd DHCPACK on 172.168.1.100 to 78:f8:82:a2:8e:49 (android-8d9562a7acd0a659) via em1_vlan300

    I'm not sure where to look from here? Thanks.



  • Have you seen or had the opportunity to see if this happens with other phones? You have disabled DHCP on the AP? Are you running squid proxy/squidguard? I have seen the same issue. However, it is usually after changing settings on my AP. I run OpenWRT and if I mess with txpower or try using an improper channel it will do this.


  • LAYER 8 Netgate

    The client keeps asking for a lease and the server is providing one.

    Not sure how you think that's the server's fault.



  • @maverik1:

    Have you seen or had the opportunity to see if this happens with other phones? You have disabled DHCP on the AP? Are you running squid proxy/squidguard? I have seen the same issue. However, it is usually after changing settings on my AP. I run OpenWRT and if I mess with txpower or try using an improper channel it will do this.

    I've not had the opportunity to try other phones yet. The only other wireless devices I have are my laptop and PS4 and they don't have any problems. Correct DHCP is disabled on the AP, which is an Asus RT-N66R with Asuswrt-merlin and in AP mode I don't think it even has the option to run a DHCP server as far as I can see. I've tried resetting it to factory settings and reconfiguring it. I could play with the txpower and channels but I chose the one it's on because it showed the least interference on a wifi scanner app. Also no, no proxies on my network.

    I have no idea if this is a pfSense problem, Asus problem, Android or LG problem. I just thought I'd start here because the problem started after adding pfSense to the picture. Don't mean to offend anyone  ::) Thank you all for the help


  • LAYER 8 Netgate

    Look at the pcap. the DHCP server is doing everything it needs to do every time it gets a DHCPDISCOVER.

    Concentrate on why that device thinks it constantly needs to do that. My guess: something in the way that device talks to that AP.



  • What happens if you assign a static IP for your device?


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