DHCP as server

What is Dynamic Host Configuration Protocol (DHCP)? Dynamic Host Configuration Protocol (DHCP) is network protocol for automatically assigning TCP/IP information to client machines. Each DHCP client connects to the centrally- located DHCP server which returns that client's network configuration including IP address, gateway, and DNS servers.

Dynamic Host Configuration Protocol (DHCP) is a network protocol that enables a server to automatically assign an IP address to an individual computer's TCP/IP stack software. DHCP assigns a number dynamically from a defined range of numbers (i.e., a scope) configured for a given network.IP address TCP/IP

Almost all wireless access points, many wired Ethernet routers, and computers running Internet Connection Sharing have built-in DHCP servers. While this makes configuration of a small network easier, it can cause problems when the DHCP servers are used in larger networks. For this reason, Indiana University prohibits individuals and departments from setting up local DHCP servers on the IU network.wireless access pointsEthernetInternet Connection Sharing

Client computers configured to use DHCP for IP assignment do not need to have a statically assigned IP address. In addition, they generally do not need to have addresses configured for DNS servers or WINS servers, as these are also set by the DHCP serverDNS WINS

Sequence A user turns on a computer with a DHCP client. The client computer sends a broadcast request (called a DISCOVER or DHCPDISCOVER), looking for a DHCP server to answer. The router directs the DISCOVER packet to the correct DHCP server when the server resides outside the network.packet The server receives the DISCOVER packet. Based on availability and usage policies set on the server, the server determines an appropriate address (if any) to give to the client. The server then temporarily reserves that address for the client and sends back to the client an OFFER (or DHCPOFFER) packet, with that address information. The server also configures the client's DNS servers, WINS servers, NTP servers, and sometimes other services as well. The client sends a REQUEST (or DHCPREQUEST) packet, letting the server know that it intends to use the address. The server sends an ACK (or DHCPACK) packet, confirming that the client has a been given a lease on the address for a server-specified period of time.

Dynamic vs Static Clients : dynamic Servers : static Static dynamic assigned ip ? Admins ? Special use... Split scope static and dynamic

Why you need DHCP server? DHCP is useful for fast delivery of client network configuration. When configuring the client system, the administrator can choose DHCP and not have to enter an IP address, netmask, gateway, or DNS servers. The client retrieves this information from the DHCP server. DHCP is also useful if an administrator wants to change the IP addresses of a large number of systems. Instead of reconfiguring all the systems, he can just edit one DHCP configuration file on the server for the new set of IP address.server If the DNS servers for an organization changes, the changes are made on the DHCP server, not on the DHCP clients. Once the network is restarted on the clients (or the clients are rebooted), the changes will take effect.network if a laptop or any type of mobile computer is configured for DHCP, it can be moved from office to office without being reconfigured as long as each office has a DHCP server that allows it to connect to the network.mobile computer

Installation on debian Apt-get update Apt-get install dhcp3-server

/etc/dhcp3/dhcpd.conf option domain-name "test1.com"; option domain-name-servers , ; option routers ;routers default-lease-time 3600; subnet netmask { arrange ; }

Static DHCP config host hostname { hardware ethernet 00:B0:CF:8B:49:37; fixed-address ; }

Restart daemon /etc/init.d/dhcp3-server restart

Verify working cd /var/log tail –f messages Ipconfig or ipconfig on client pc’s

RFC information