Domain Name System

Cisco routers can participate in the Domain Name System (DNS). For example, you can specify a default domain name that the Cisco IOS Software uses to complete domain name requests. You can specify either a single domain name or a list of domain names. Any IP hostname that does not contain a domain name has the domain name you specify appended to it before being added to the host table. To specify this domain name, use the following command:
Router(config)# ip domain name name

To define a list of default domain names to complete unqualified host names, we use the following command:

Router(config)# ip domain list name

We can also specify DNS name servers for the router or switch to call on for name resolution. To do so, use the following command:

Router(config)# ip name-server server-address1 [serveraddress2 server-address6]

If you do not want to enable your router to use DNS for name resolution, you can use the following command to disable this default behavior:

Router(config)# no ip domain-lookup