DNS Configuration on Cisco Routers

To use DNS, a DNS Server must be configured. In a network, a router can be configured as DNS Server. In this lesson, we will talk about how to configure a Cisco Router to serve as a DNS Server in a network.

For our DNS Server Configuration Example, we will use the below topology:

To configure a Cisco Router as a DNS Server, we need to follow some basic configuration steps. These Cisco DNS Server configuration steps are given below:

1. Enable DNS Server
2. Enable Domian Lookup
3. Public Name Server Configuration
4. Host / IP Address Mappings
5. Router Interface IP Configuration
6. Hosts IP Configuration
7. Configuration Verification

Now, let’s configure our Cisco Router as a DNS Server with the above steps.

Enable DNS Server

To enable DNS Server, we will use “ip dns server” command. With this command, our router is becoming a DNS Server.

RouterA # configure terminal 
RouterA (config)# ip dns server

Enable Domain Lookup

To enable Domain Lookup we will use “ip domain-lookup” command.

RouterA (config)# ip domain-lookup

Public Name Servers Configuration

On the router, we will configure Public Name Servers. With this configuration, our DNS Server router will ask to the configured Public DNS Servers for every DNS Requests and replied back. Here, you can use any Public DNS Server addresses.

RouterA (config)# ip name-server 1.1.1.1 
RouterA (config)# ip name-server 2.2.2.2

Host / IP Address Mappings

In this step, we will give the hostnames and their ip addresses to the DNS Server manually. With these information, DNS Server can answer to the requests coming by hostnames with IP addresses.

Other DNS Articles
Domain Name System – DNS Overview
Domain Name System – DNS Configuration on Cisco