Cisco Systems 700 manual Dhcp Description, Dhcp Server Application Notes

DHCP Description

DHCP Description

DHCP is a client-server protocol that allows devices on an IP network (the DHCP clients) to request configuration information from a DHCP server. DHCP allocates network addresses from a central pool on an as-needed basis. DHCP is useful for assigning IP addresses to hosts connected to the network temporarily or for sharing a limited pool of IP addresses among a group of hosts that do not need permanent IP addresses.

DHCP allows for increased automation and fewer network administration problems by:

•Eliminating the need for the manual configuration of individual computers, printers, and shared file systems.

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Preventing the simultaneous use of the same IP address by two clients.

Allowing configuration from a central site.

DHCP Server Application Notes

The following are application notes for DHCP server:

•DHCP relay and DHCP server are mutually exclusive.

•When DHCP server is initialized, default addresses are used if no LAN or internal address exists. The Cisco 700 series router picks up the DHCP client’s default gateway, netmask, and starting DHCP addresses by using the LAN IP address, if one exists. If a LAN address does not exist, the router uses the internal IP address. If neither exists, it uses the default settings: 10.0.0.1 as the LAN IP address (default gateway for DHCP clients), 255.0.0.0 as the subnet mask, and 10.0.0.2 as the starting DHCP client addresses.

•For the DHCP values to be automatically generated based on the LAN or internal IP address, each DHCP value must be set to 0.0.0.0 or none, for the new values to take effect.

5-2Cisco700 Series Router Configuration Guide