Problem: Despite the setting "Allow unknown clients" at the DHCP pool, no IP addresses are distributed to unknown devices

dhcp

#1

Problem:

Despite the setting “Allow unknown clients” at the DHCP pool, no IP addresses are distributed to unknown devices.

Investigation:

The dhcp configuration is stored in ldap. To make the used configuration visible you can enable the “debug” in

/etc/dhcp/dhcpd.conf
ldap-debug-file "/var/log/dhcp-ldap-startup.log";

If the configuration looks like this with a subnet and a pool:

------8< ----------------------------------------
subnet 10.200.43.0 netmask 255.255.252.0 {
option routers 10.200.43.1;
option domain-name "schein.me";
option domain-name-servers 10.200.0.10;
deny unknown-clients;
allow bootp;
pool {
range 10.200.46.250 10.200.46.254;
deny known clients;
allow unknown clients;
deny dynamic bootp clients;
option routers 10.200.43.1;
option domain-name "schein.me";
option domain-name-servers 10.200.0.10;
max-lease-time 86400;
default-lease-time 28800;
deny unknown-clients;
}
}
---------------->8----------------------

The problem is that the default policy defined for the service (cn=default-allow-verbieten) is inherited by all subnets and the definition no longer applies to the individual pools.

Solution:

The definition at the service must not be set to make the confiugration work for the defined pools.


#2