ISC DHCP, Webmin GUI tool By Vikas Bagwe Day1 Introduction to ISC-DHCP Server & Webmin Interface The IP subnet creation & modification CPE Replacement CPE Reuse CPE Removal Troubleshooting DHCP Day2 Hand’s on training on CPE Replacement/Reuse/Removal Hand’s on training IP subnet creation & modification. ISC-DHCP Server, The most common open source DHCP server software for Unix system is the ISC server, it supports a wide range of options, and can be configured to behave differently for different clients, networks and address ranges. Supports assigning fixed addresses to hosts, or addresses from certain ranges. Every host is identified by its MAC addresses. Entries in the server configuration are arranged in a hierarchy that determines what client options and other settings apply to a particular client. Options in higher-level entries are overridden by those lower in the hierarchy, which allows an administrator to avoid repeating configuration information while still being able to set individual options for specific hosts. The ISC DHCP server's primary configuration file is called dhcpd.conf, and can usually be found in the /usr/local/etc directory. Other configuration files can be included by the primary file, the info of which can be found in dhcpd.conf file defined with include option. The only other file used by the server is dhcpd.leases, which contains all granted leases and is always kept up to date. Whenever the server is started, it re-reads this file to find out which leases are currently active. Webmin is a GUI interface for system administration for Unix. It is a open source software. Using any modern web browser, you can access its GUI interface. Webmin supports DHCP server configuration & maintenance with its DHCP server module. Webmin's DHCP Server module directly updates the configuration and lease files when you manage subnets, hosts, groups and leases. Additionally it reports Dynamic IP pool utilization & provides The List DHCP Leases option when it used it scans the entire dhcpd.leases file hence the time taken to list leases is directly proportional to Lease file size.