Cisco Systems 78-11741-02 manual Assigning Host Names to IP Addresses, Specifying the Domain Name

Configuring IP Addressing

Configuring Address Resolution Methods

To keep track of domain names, IP has defined the concept of a name server, whose job is to hold a cache (or database) of names mapped to IP addresses. To map domain names to IP addresses, you must first identify the host names, then specify a name server, and enable the Domain Naming System (DNS), the global naming scheme of the Internet that uniquely identifies network devices. These tasks are described in the following sections:

•Assigning Host Names to IP Addresses

•Specifying the Domain Name

•Specifying a Name Server

•Enabling the DNS

•Using the DNS to Discover ISO CLNS Addresses

Assigning Host Names to IP Addresses

The Cisco IOS software maintains a table of host names and their corresponding addresses, also called

ahost name-to-address mapping. Higher-layer protocols such as Telnet use host names to identify network devices (hosts). The router and other network devices must be able to associate host names with IP addresses to communicate with other IP devices. Host names and IP addresses can be associated with one another through static or dynamic means.

Manually assigning host names to addresses is useful when dynamic mapping is not available.

To assign host names to addresses, use the following command in global configuration mode:

Command	Purpose
Router(config)# ip host name [tcp-port-number]	Statically associates host names with IP addresses.
address1 [address2...address8]

Specifying the Domain Name

You can specify a default domain name that the Cisco IOS software will use to complete domain name requests. You can specify either a single domain name or a list of domain names. Any IP host name that does not contain a domain name will have the domain name you specify appended to it before being added to the host table.

To specify a domain name or names, use either of the following commands in global configuration mode:

Command	Purpose
Router(config)# ip domain name name	Defines a default domain name that the Cisco IOS software will use
	to complete unqualified host names.
Router(config)# ip domain list name	Defines a list of default domain names to complete unqualified host
	names.

See the “IP Domains Example” section at the end of this chapter for an example of establishing IP domains.

Cisco IOS IP Configuration Guide

IPC-16