DHCPNAK no lease left

I have 1 host which for one or another reason is unable to get an IP address. I have a scope of 30 address between 110-130 and almost every host has an IP reservation outside this scope so there are plenty of free addresses available.

If I don’t reserve the IP for the host i just receive a DHCPNAK
Jun 6 18:34:04 sme10 dnsmasq-dhcp[2540]: DHCPREQUEST(eth0) 192.168.x.110 xx:xx:xx:c7:2f:56
Jun 6 18:34:04 sme10 dnsmasq-dhcp[2540]: DHCPNAK(eth0) 192.168.x.110 xx:xx:xx:c7:2f:56 no leases left

If i make an IP reservation for the host I still get an DHCPNAK
Jun 6 18:53:28 sme10 dnsmasq-dhcp[2540]: DHCPDISCOVER(eth0) xx:xx:xx:c7:2f:56
Jun 6 18:53:28 sme10 dnsmasq-dhcp[2540]: DHCPOFFER(eth0) 192.168.x.105 xx:xx:xx:c7:2f:56
Jun 6 18:53:29 sme10 dnsmasq-dhcp[2540]: DHCPREQUEST(eth0) 192.168.x.105 xx:xx:xx:c7:2f:56
Jun 6 18:53:29 sme10 dnsmasq-dhcp[2540]: DHCPNAK(eth0) 192.168.x.105 xx:xx:xx:c7:2f:56 no leases left

I’m puzzled? Anyone who can give me an hint how to solve this? The client works fine if I set a fixet IP. The problem started when i restarted the dnsmasq service to fix as a workaround to the openvpn bind problem.

No the problem propagates to other devices and I have 3 more devices who has this problem now. I have restarted the server and dnsmasq to fix the error with DNS.

Any suggestions are appreciated.

If dnsmasq is out of reservations, the lease cache should contain them: have a look to the contents of


maybe it is an OpenVPN problem ? Are U push to VPN users DHCP from dnsmasq?

Sorry for late response. I’m on vacation with very bad wifi. The problem is on the LAN. I’ll check out your suggestion as soon I get wifi back up in our bungalows. I thought it could be the lease but never found out we’re to verify it because I didn’t find it in the dnsmasq confit file. We’re do I have to change the settings for leases so it becomes permanent?

aahaha “NethServer on Bungalows” :sailboat: :tent:
Please take a photo and upload it here

Finally home a possible to check the settings. I have 20 leases in the cache were do i check the settings for how many leases are set in DNSMASQ and were to I change the settings permanently?

For bungalows make leases every 15 min and it would solve your problem!

I ment were is the DB settings for dhcp max allowed leases or something similar so I can override it? I have both checked db dhcp show and db configuration show dnsmasq and lastly db configuration show but I can’t find a relevant key there to override?

U need to add key DhcpLeaseTime to dnsmasq db , try and say does it works


you have to check in /templates/ tree the relevant fragment and see if it handles such a variable.

if so, then change it via db command

if not, create a custom fragment in /templates-custom/ tree to override

that’s the way NS works


please, when you answer, you’d be verbose…

so, instead of

you’d say

in this way you help @malvank (and others) to find a solution

moreover, a

db configuration show | grep -i dhcplease

would help


now im from phone and have no time to check
db configuration setprop dnsmasq DhcpLeaseTime 3600
signal-event nethserver-dnsmasq-update
could help but no time to check and in
my $lease = $_->prop(‘DhcpLeaseTime’) || ‘86400’;

so i’l make custom templete later

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well done, thank you

so @giacomo @filippo_carletti @alefattorini changes to dnsmasq db doesnot work! but why ? is it a bug ?

and solution is one @malvank :
mkdir /etc/e-smith/templates-custom/etc/dnsmasq.conf
cp /etc/e-smith/templates/etc/dnsmasq.conf/30dhcp /etc/e-smith/templates-custom/etc/dnsmasq.conf/30dhcp
edit :
my $lease = $->prop(‘DhcpLeaseTime’) || ‘86400’;
my $lease = $
->prop(‘DhcpLeaseTime’) || ‘900’;

run signal-event nethserver-dnsmasq-update
and be happy !

next solution is :
edit /etc/e-smith/templates-custom/etc/dnsmasq.conf/30dhcp
coment out my $lease = $_->prop(‘DhcpLeaseTime’);
my $lease = $dnsmasq{‘LeaseTime’};
then add value as you need in seconds for lease time
db configuration setprop dnsmasq LeaseTime 900
signal-event nethserver-dnsmasq-update

I think that the DhcpLeaseTime prop there is a leftover of the times when we had only a range for green. When we added support for dhcp on blue, the prop moved to the dhcp db.
The command would be:
db dhcp setprop eth0 DhcpLeaseTime 6000
(where eth0 is the interface)

I’ve drafted a server-manager panel to adjust a lot of the dhcp options, stay tuned.

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And do not forget about transparent proxy by ip of the server :slight_smile:

@zamboni @Nas Thank you for your assistance and the solution proposal. I looked into the template layout and I start to understand the setup so much better now but still I’m a bit puzzled. First of all I don’t know why your suggestions is on DhcpLeaseTime, I think my problem is more related that the DHCP is not assigning more than 20 IP addresses and therefore I think the correct solution has to be related with the dhcp-lease-max parameter? I suppose the lease time has some effect for the cache but hence it is set to 24h it’s shouldn’t be of to much of an problem for my scenario.

@filippo_carletti I looked into the template layout cat /etc/e-smith/templates/etc/dnsmasq.conf/30dhcp for the dhcp settings and found out that the dhcp-lease-max is set to if ($tot_range_length > 0) { $OUT .= "dhcp-lease-max=$tot_range_length\n"; } so before I make a complete fool out of myself can you or someone else please tell me if IP reserved IP-addresses are counted into the the value of dhcp-lease-max? I hope not but I fear the oposite.

You could check it simply! So when you have Dhcp error, you could count max values of comp in dhcp.lease file and then you could make some desigions! but i have dnsmasq on wifi routers , all work like a charm without problem.
run cat /var/lib/dnsmasq/dnsmasq.leases | wc -l
and tell us :slight_smile: