2011-12-05

DNS Services Command List

DNS Services Command List

The Domain Name System (DNS) is a database that maps logical host names to IP addresses. The following table describes the difference between a router and a workstation when resolving a logical host name to an IP address:

Device

Details

Router

A router's DNS name resolution looks for information in the following places (in this order):

  1. Static DNS entries
  2. DNS server query (if enabled)

Workstation

A workstation's DNS name resolution looks for information in the following places (in this order):

  1. Local DNS cache
  2. HOSTS file
  3. DNS server query (Primary)
  4. DNS server query (Secondary)

Note: Additional DNS servers are only consulted if the primary DNS server did not respond (i.e. it is offline).

Use the following commands to configure DNS services on a router:

Use...

To...

router(config)#ip host <name> a.b.c.d

Create static DNS entries

router(config)#ip domain-name <name>

Configure the router default domain (for DNS)

router(config)#ip name-server a.b.c.d

Set the default DNS name server

router(config)#ip domain-lookup

Enable the router to use DNS to identify IP addresses from host names

router(config)#no ip domain-lookup

Disable the broadcast name resolution of host names.

router#show hosts

Display a list of known IP hosts

Tidak ada komentar: