Cisco Systems 78-11741-02 manual Specifying a Name Server, Enabling the DNS, IPC-17

Configuring IP Addressing

Configuring Address Resolution Methods

Specifying a Name Server

To specify one or more hosts (up to six) that can function as a name server to supply name information for the DNS, use the following command in global configuration mode:

Command	Purpose
Router(config)# ip name-server	Specifies one or more hosts that supply name information.
server-address1
[server-address2...server-address6]

Enabling the DNS

If your network devices require connectivity with devices in networks for which you do not control name assignment, you can assign device names that uniquely identify your devices within the entire internetwork. The global naming scheme of the Internet, the DNS, accomplishes this task. This service is enabled by default.

To re-enable DNS if it has been disabled, use the following command in global configuration mode:

Command	Purpose
Router(config)# ip domain lookup	Enables DNS-based host name-to-address translation.

See the “Dynamic Lookup Example” section at the end of this chapter for an example of enabling the DNS.

Using the DNS to Discover ISO CLNS Addresses

If your router has both IP and ISO Connectionless Network Service (ISO CLNS) enabled and you want to use ISO CLNS network service access point (NSAP) addresses, you can use the DNS to query these addresses, as documented in RFC 1348. This feature is enabled by default.

To disable DNS queries for ISO CLNS addresses, use the following command in global configuration mode:

Command	Purpose
Router(config)# no ip domain-lookup	Disables DNS queries for ISO CLNS addresses.
nsap

Cisco IOS IP Configuration Guide

IPC-17