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Deus Ex Machina » Eventlog » Event 1002 - Dhcp

Dhcp - 1002


Error

Description »
The IP address lease 172.16.68.138 for the Network Card with network address 005056990007 has been denied by the DHCP server 172.16.2.1 (The DHCP Server sent a DHCPNACK message).
Data formatted as » None

A DHCPNACK is a negative acknowledgement. The server has acknowledged your request for a specific IP address, but you can't have it. This is most commonly seen in split-scope scenarios.

Let's say you have a subnet at 192.168.1.0/24, which is used for DHCP clients. You have one DHCP server which hands out addresses 192.168.1.10-192.168.1.119, and another that hands out 192.168.1.120-192.168.1.229. Your computer makes an initial DHCPDISCOVER, and ... after a bit of back'n'forth, ends up being assigned the address 192.168.1.50, with a lease duration of one hour. A few minutes later, and.. oh noes! The DHCP server is down! Your computer soon attempts to renew the address, but the only DHCP server available doesn't have 192.168.1.50 available in its address pool, so your request to renew this address is met with a DHCPNACK, and you see this event in your system log.