semester 2 2012 week 9 - 10

dhcp setting 

The Dynamic Host Configuration Protocol (DHCP) is a network protocol that is used to configure network devices so that they can communicate on an IP network. A DHCP client uses the DHCP protocol to acquire configuration information, such as an IP address, a default route and one or more DNS server addresses from a DHCP server. The DHCP client then uses this information to configure its host. Once the configuration process is complete, the host is able to communicate on the internet.

The DHCP server maintains a database of available IP addresses and configuration information. When it receives a request from a client, the DHCP server determines the network to which the DHCP client is connected, and then allocates an IP address or prefix that is appropriate for the client, and sends configuration information appropriate for that client. It is because the DHCP protocol must work correctly even before DHCP clients have been configured, the DHCP server and DHCP client must be connected to the same network link. In larger networks, this is not practical. On such networks, each network link contains one or more DHCP relay agents. These DHCP relay agents receive messages from DHCP clients and forward them to DHCP servers. DHCP servers send responses back to the relay agent and the relay agent then sends these responses to the DHCP client on the local network link.

DHCP servers typically grant IP addresses to clients only for a limited interval. DHCP clients are responsible for renewing their IP address before that interval has expired, and must stop using the address once the interval has expired, if they have not been able to renew it.

DHCP is used for IPv4 and IPv6. While both versions serve much the same purpose, the details of the protocol for IPv4 and IPv6 are sufficiently different that they may be considered separate protocols.

Hosts that do not use DHCP for address configuration may still use it to obtain other configuration information.

          

The DHCP service is needs to be deployed on an interface configured with a static IP address. This interface should also be internal. The default gateway is the client to communicate with destinations that are not on the local network, such as the Internet. Search domain is the parameter that can be useful in a network where all the hosts are named under the same subdomain. Thus, when attempting to resolve a domain name unsuccessfully (for example host), a new attempt would be carried out by adding the search domain at the end. For the primary name server is to specify the DNS server that clients will use first when they have to resolve a domain name. Its value can be Local Zentyal DNS or the IP address of another DNS server. for the secondary name server, DNS server to be used by clients in case primary DNS server is unavailable. Its value must be an IP address of a DNS server. the NTP server is for client which is their use to synchronies their system clock. It can be None, Local Zentyal NTP or the IP address of another NTP server.

dhcp range

The purpose of range addresses is to distribute or static allocations. Otherwise the DHCP server will not allocate IP addresses even when listening on all network interfaces. The address ranges and static addresses are available for assignment from a certain interface which is not determined by the static address assigned to that interface. Any available IP address of the subnet can be used in ranges or static allocations. In order to add a range in the Range section, a name has to be introduce to identify the range and the values which is 192.168.1.100 to 192.168.1.150 where the range is from 100 to 150. Static of assignment of IP addresses are introduced to specific physical addresses in the Fixed addresses section. An object will be fill which members are pairs of host IP addresses (/32) and MAC addresses.. An address assigned in this way cannot be part of any range. An optional Description for the allocation as well will be added.