Solved dhcpd.conf default-lease-time not being honored, replaced with 1200

horseflesh

horseflesh

I've set up a new system for firewall duties and have found a small issue that I can't figure out.

In my dhcpd.conf I have specified lease times:

Code: 
default-lease-time 72000;
max-lease-time 144000;
I have also specified fixed IPs for most things on my LAN, with directives like:

Code: 
# Brother color printer is .11
host printercolor {
hardware ethernet c:fe:e6:a7:e1:9c;
fixed-address 192.168.1.11;
}
Every device gets its correct IP and dhcpd is working fine. Here's the weird thing... When I check the network status with arp -a I see lease timers counting down from 1200 seconds. For example:

Code: 
[1456][user@test:~]$ arp -a
? (192.168.1.20) at 00:1e:52:73:8a:e6 on igb1 expires in 927 seconds [ethernet]
After the countdown it will begin anew from 1200.

My dhcpd.conf is clearly getting parsed as I'm getting the IPs I expect. But somehow, my default-lease-time is not being honored.

I've scoured all the configs that I can think of for the string "1200" with no luck. What is stomping my default-lease-time?

System details:

FreeBSD 11 amd64 with GENERIC kernel, running only ipf, ipnat, DHCP. Configs were copied from a FreeBSD 8 system so there could be a version issue... but if so I can't find it.

Thanks!
 
The ARP timers have nothing to do with DHCP lease times, although I can see why you could confuse the two.
DHCP assigns an IP address to a single requester, these are broadcast/unicast using udp port 67 (ie tcpdump port 67).
ARP keeps track of the MAC/IP address map, these are broadcast using the ARP protocol (ie tcpdump arp) to tell everybody else on the network what DHCP just did for you.
 
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