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Network Services—Local Network ServicesAccording to our configuration, the default lease time for each address is 600 seconds(10 minutes), if the client does not request any specific lease time. The maximumpossible lease time we have specified is 7200 seconds (2 hours). You may want tomodify these parameters according to your network configuration and resources.To keep track of assigned IP addresses, DHCP server maintains a lease file at /var/db/dhcpd/dhcpd.leases. This is where DHCP server writes down the IP addressesassigned to each client, and whether the leases are active or inactive. The file alsocontains additional information about each client, such as MAC address. This addressis used to identify unique hosts, as well as start and end times for leases and alsothe binding state field. This will be useful for a system administrator to see whichsystems are online and have active leases (by looking at binding state field) andwhich hosts are not online. You can also modify this file to remove inactive leases,or easily assign a specific IP address to each client. Removing this file will lead theDHCP server to lose track of its assignment history, and all the leases will be reset.The following sample shows a dhcpd.leases file that contains two entries, thefirst entry for an expired (and reserved) address and the second entry for an active(currently assigned) IP address as shown here:# cat /var/db/dhcpd/dhcpd.leaseslease 192.168.0.220{starts 0 2008/03/16 17:25:09;ends 0 2008/03/16 17:35:09;tstp 0 2008/03/16 17:35:09;binding state free;hardware ethernet 00:18:f3:03:f4:5b;uid "\001\000\030\363\003\364[";}lease 192.168.0.219{starts 0 2008/03/16 19:22:01;ends 0 2008/03/16 19:32:01;binding state active;next binding state free;hardware ethernet 00:a0:d1:3d:00:dd;uid "\001\000\240\321=\000\335";client-hostname "pixel";}[ 238 ]