[Dnsmasq-discuss] Problems with DHCP and 2.38

[Simon Kelley]

Davide Ferrari wrote:
> Hello
> 
> yesterday I upgraded dnsmasq from older 2.31 to the newest 2.38, and this 
> morning I noticed several problems with DHCP assignments.
> There were tons of "DHCPNAK no leases left" referred to DHCPREQUEST from 
> clients while:
> - /var/lib/misc/dnsmasq.lease didn't contain said IP
> - ping/arping to that IP showed that IP was free
> - dhcp range in dnsmasq.conf was greater than "cat dnsmasq.lease |wc -l"
> 
> Now I am back to 2.31, I deleted the old dnsmasq.lease and now DHCP seems to 
> work again well.

"no leases left" means that the limit on the number of leases has been
reached. There's a distinction between addresses and leases. The default
for the limit on number of leases is 150, and always has been. You can
increase it with --dhcp-lease-max

> I can't understand what happened here...
> 

I can't simply explain why 2.31 works but 2.38 doesn't. If you are close
to the limit, then it's possible that changes in the way leases are
released might be enough to cause the difference (leases hang around for
a short while now, as part of the --dhcp-script code.)

How many leases do you have in existance? If it's around 150, then
increase the limit and see if that fixes the problem.

Cheers,

Simon.