DHCP client failure to obtain address

packetuser · Feb 23, 2018, 2:25 AM

Greetings,

I'm using 2.3.4 on a Netgate 5501, and recently I had an issue where the pfsense DHCP client failed to get an IP from my ISP. A workstation connected to the router had no problem getting an IP. Curiously, the pfsense box also exhibited a periodically high ping during the DHCP problem:

64 bytes from 192.168.1.1: icmp_seq=6 ttl=64 time=369.383 ms
64 bytes from 192.168.1.1: icmp_seq=7 ttl=64 time=3.847 ms
64 bytes from 192.168.1.1: icmp_seq=8 ttl=64 time=3.437 ms
64 bytes from 192.168.1.1: icmp_seq=9 ttl=64 time=645.179 ms
64 bytes from 192.168.1.1: icmp_seq=10 ttl=64 time=3.934 ms
64 bytes from 192.168.1.1: icmp_seq=11 ttl=64 time=130.470 ms
64 bytes from 192.168.1.1: icmp_seq=12 ttl=64 time=3.792 ms
64 bytes from 192.168.1.1: icmp_seq=13 ttl=64 time=4.073 ms

I attempted to perform a packet capture on the WAN interface, but the capture file was empty.

dpinger shows the following error:

Feb 22 21:02:01 dpinger send_interval 500ms loss_interval 2000ms time_period 60000ms report_interval 0ms data_len 0 alert_interval 1000ms latency_alarm 500ms loss_alarm 20% dest_addr [WAN IP] bind_addr [another IP similar to WAN] identifier "WAN_DHCP "

The DHCP log shows (partially):

Feb 22 20:58:34 dhclient 77757 DHCPDISCOVER on vr1 to 255.255.255.255 port 67 interval 9
Feb 22 20:58:43 dhclient 77757 DHCPDISCOVER on vr1 to 255.255.255.255 port 67 interval 13
Feb 22 20:58:57 dhclient 77757 No DHCPOFFERS received.
Feb 22 20:58:57 dhclient 77757 No working leases in persistent database - sleeping.
Feb 22 20:58:57 dhclient FAIL
Feb 22 21:01:51 dhclient PREINIT
Feb 22 21:01:52 dhclient EXPIRE
Feb 22 21:01:52 dhclient Deleting old routes
Feb 22 21:01:52 dhclient PREINIT

Then after a reboot, the DHCP problem disappeared. Any tips for what troubleshooting steps I can take? Thanks in advance!

Gertjan · Feb 23, 2018, 7:28 AM

Hi,

Start eliminating NIC problems by, for example, switch LAN and WAN.

packetuser · Feb 23, 2018, 1:38 PM

Thanks Gertjan. The problem appears to be a software issue, since it is resolved after a reboot. Are you aware of a software bug that would cause issues isolated to one NIC?

Gertjan · Feb 23, 2018, 9:03 PM

Yes, one word : realtek