When the DHCP server provides an IP address, the client performs an ARP check to make sure the address is not being used by another client and reports any conflicts back to the server. The server keeps track of addresses with conflicts and removes them from the address pool. Use the CLI command show system services dhcp conflict to show conflicts.
user@host> show system services dhcp conflict
Detection time Detection method Address 2004-08-03 19:04:00 PDT client 192.168.1.5 2004-08-04 04:23:12 PDT ping 192.168.1.8
Use the clear system services dhcp conflicts command to clear the conflicts list and return IP addresses to the pool. The following command shows how to clear an address on the server that has a conflict:
user@host> clear system services dhcp conflict 192.168.1.5
Note: For more information about CLI commands you can use with the DHCP server, see the JUNOS System Basics and Services Command Reference.