DHCPD no free leases
 

I'm getting an error similar to this

DHCPDISCOVER from 00:40:96:40:38:f8 via eth0: network 10.0.0.0/24: no free lease

Can someone help me please?

Thanks

Can you post your dhcpd.conf file?

ddns-update-style none;

#Define WPAD-URL as a valid code
#Used for Automatically detect proxy settings

option wpad code 252 = text;

shared-network SHLAX-NET {

authoritative;

# Deny unknown
subnet 192.168.9.0 netmask 255.255.255.0 {
#Known clients get this pool
pool {
option routers 192.168.9.254;
option domain-name "sheratonlax.thekorgroup.local";
option domain-name-servers 192.168.9.33;
option netbios-name-servers 192.168.9.33;

#Automatically detect settings - Used for AutoProxy configuration
#option wpad "http://wpad/wpad.dat/\n";

range 192.168.9.101 192.168.9.200;
default-lease-time 604800;
max-lease-time 1296000;

deny unknown-clients;

group {
host jsmithLAN { hardware ethernet 00:0d:56:ad:b1:f4; }
host hskp-geac { hardware ethernet 00:60:97:13:e0:9d; }
host aidan-lap { hardware ethernet 00:12:3f:0e:dd:5d; }
host jsmithWireless { hardware ethernet 00:90:4b:66:06:7a; }
host hsi-printer { hardware ethernet 00:80:44:0c:d6:d2; }
} #end group
} #end pool
} #end subnet

subnet 172.18.50.0 netmask 255.255.255.0 {
# Unknown clients get this pool
pool {
option routers 172.18.50.1;
option domain-name "no-internet.local";
option domain-name-servers 172.18.50.33;

range 172.18.50.100 172.18.50.200;
default-lease-time 1800;
allow unknown-clients;
} #end pool
} #end subnet
}




Thanks

I just deleted dhcpd.leases and rebooted. Things seem to be in places now. Anyone is welcome to post a more justified answer.

Thanks

Workaround for this issue
 

This and similar errors RECENTLY started happening to me too. It appears that dhcpd made a significant change in how it handles ranges assigned to a subnet. It appears that if you have any hosts with a fixed-address that exists in your range, the entire range is ignored for anything other than your host entries! This IMHO is a step backwards, but here is my workaround (declare every address in your range as a range itself):

Let me break it down for you
 

Alright, I got into a pissing contest with the Network Engineer here about why a device wouldn't complete an IP lease, here is my win:

I've placed X's in IP addresses for security.

1. DHCP Block in /etc/dhcp.master (includes failover config for our HA dhcp cluster, dont get lost/overwhelmed):

2. An example lease in /var/lib/dhcpd/dhcpd.leases(the file that shows all leases for your defined DHCP ranges):

Now, since my DHCP network is 19x.60.23x.120 255.255.255.248, as defined by Step 1., .120 is the network, .121 is the Gateway. .122-126 are usable addresses, and .127 would be the broadcast address.

Imagine there being a lease for .122-126 in the dhcp.leases file as defined in step 2., so I dont inflate this reply with superfluous confusion.

when a 6th device tries to lease an address on this network via DHCP, you'll see this in /var/log/dhcpd:

going back to Step 2., notice that there is a stard/end (end being expiration) to the lease:

Plain and simple, a new device isn't giong to get an IP address until leases have expired. Adding a "new" device to the network and you're not able to get an IP via DHCP (even if there are under the limited amount of devices on the DHCP network)? Clear the leases out of /var/lib/dhcpd/dhcpd.leases, save, and try again.

No, arp caches are not the issue here. clearing the arp cache on your routers/switches doesn't free up DHCP space, and it doesn't give a single switch port a free slot for your new device to ARP up with.

This entire battle came from the following arp entry in a cisco router:

Protocol Address Age (min) Hardware Addr Type Interface
Internet 20x.8x.9x.2x4 0 Incomplete ARPA



I hope this is helpful.