Common error messages in the dhcpd log

peer holds all free leases

dhcpd: DHCPDISCOVER from 3c:c9:3b:a0:58:2b via 10.123.23.129: peer holds all free leases

A static entry that was out of the subnet range (i.e. a wrong subnetmask in the subnet declaration).

unknown subnet for client address

dhcpd: DHCPINFORM from 192.168.56.1 via 10.123.36.1: unknown subnet for client address 192.168.56.1

The client is in a wrong vlan, possibly a laptop comming from another network.

xid mismatch

dhcpd: bind update on 10.123.38.197 got ack from dhcp-failover: xid mismatch.

?? unimportant

Dynamic and static leases present

dhcpd: Dynamic and static leases present for 10.123.65.108.
dhcpd: Remove host declaration !MM7MZ21RSJSJO9 or remove 10.123.65.108
dhcpd: from the dynamic address pool for 10.123.65.0/24

Here you have a static entry (hardware ethernet / fixed-address) inside a dynamic range. Is is not recomended, but it works (this IP is not offered to an other client).

is duplicate on

dhcpd: uid lease 10.123.39.227 for client 00:33:19:45:fc:c7 is duplicate on 10.123.36.0/22

??? some sort of IP collision (autosolved)

dhcp-failover rejected

bind update on 10.132.131.101 from dhcp-failover rejected: incoming update is less critical than outgoing update

todo

wrong network

dhcpd: DHCPREQUEST for 10.123.51.25 from 3c:a7:0e:da:ff:9c (pcyi1340-0117) via 10.123.65.2: %RED%wrong network%ENDCOLOR%.
dhcpd: DHCPNAK on 10.123.51.25 to 3c:a7:0e:da:ff:9c via 10.123.65.2

laptop comming from another network.

BOOTREPLY

dhcpd: BOOTREQUEST from 00:45:b7:1e:45:b6 via 10.123.36.1
dhcpd: BOOTREPLY on 10.123.37.90 to 00:45:b7:1e:45:b6 via 10.123.36.1

todo

Abandoning IP address pinged before offer

dhcpd: Abandoning IP address 10.123.36.156: pinged before offer

IP is occupied by other client. The dhcpd tries to ping the IP he likes to offer (ping-check true;). If he get a reply, there is something wrong in his pool counting. He marks this IP as abandoned and offers an other IP.

abandoned

dhcpd: DHCPREQUEST for 10.123.244.252 (10.100.188.150) from e8:9a:8f:3f:09:0c via 10.123.244.2
dhcpd: DHCPACK on 10.123.244.252 to e8:9a:8f:3f:09:0c via 10.123.244.2
dhcpd: DHCPDECLINE of 10.123.244.252 from e8:9a:8f:3f:09:0c via 10.123.244.3: %RED%abandoned%ENDCOLOR%

IP is occupied by other client. Similar to the case befor: The dhcpd tries to ping the IP he likes to offer (ping-check true;). The faulty client does NOT reply to ping. The dhcpd offers this IP to the new client AND the clients checks the IP by himself through a arp request for his offered IP. If the gets a reply he knows the IP is occupied and sends a DHCPDECLINE to the dhcpd. The dhcpd will count this IP as abandoned for some time.

not found

dhcpd: DHCPDISCOVER from 00:c0:b7:82:b1:fa via 10.186.30.1
dhcpd: DHCPOFFER on 10.123.30.43 to 00:c0:b7:82:b1:fa via 10.123.30.1
dhcpd: DHCPREQUEST for 10.123.30.43 (10.22.188.150) from 00:c0:b7:82:b1:fa via 10.123.30.1
dhcpd: DHCPACK on 10.123.30.43 to 00:c0:b7:82:b1:fa via 10.123.30.1
dhcpd: DHCPDECLINE of 10.123.30.43 from 00:c0:b7:82:b1:fa via 10.123.30.1: %RED%not found%ENDCOLOR%

IP is occupied by other client. Same as befor, but the client replies a not found (in this case a APC UPS)

unknown network segment

dhcpd: DHCPDISCOVER from fa:e1:d5:3b:a2:e1 via 10.123.114.3: %RED%unknown network segment%ENDCOLOR%

The client is requesting an IP for a network unkown to the dhcp server (server has no config for this network).