Polycom 1725-31424-001 manual Dhcp and the Polycom CX700 IP Phone, Dhcp Search Options

Deployment Guide for the Polycom CX700 IP Phone

For the most up-to-date version of the Deploying Microsoft Office Communicator 2007 R2 Phone Edition documentation and the complete set of the Microsoft® Office Communications Server 2007 R2 online server and client documentation, see the Office Communications Server TechNet Library at http://go.microsoft.com/fwlink/?LinkID=132106.

DHCP and the Polycom CX700 IP Phone

All computers that are on a TCP/IP network must have an IP address for the network to work correctly. Generally, you can manually configure IP addresses at each computer, or you can install a Dynamic Host Configuration Protocol (DHCP) server that automatically assigns IP addresses to each client computer or device on the network. The Polycom CX700 phone is no exception and therefore can receive only DHCP-assigned IP addresses and requires no configuration on the device.

A DHCP client is any network-enabled device that enables you to communicate with a DHCP server to obtain dynamic, leased IP configuration and related optional information. The Polycom CX700 phone is a DHCP client.

DHCP Search Options

To complete unqualified domain name system (DNS) names that will be used to search and submit DNS queries at the client for resolution, you must have a list of DNS suffixes that can be appended to these DNS names. For DHCP clients, this can be set by assigning the DNS domain name option (Option 15) and providing a single DNS suffix for the client to append and use in searches.

In some circumstances it is preferable that a DHCP client be configured by using multiple DNS suffixes, supported with the use of DHCP Search Option 119.

DHCP Search Option 119 is passed from the DHCP server to the DHCP client to specify the domain search list used when resolving hostnames with DNS. DHCP Search Option 119 applies only to DNS and does not apply to other name resolution mechanisms.

DHCP Option	Description
015	Specifies the connection-specific DNS domain suffix to
	be used by the DHCP client.
119	DNS Domain Search List option to specify the domain
	search list used when resolving hostnames with DNS.

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