DNS is an application layer protocol that is used to resolve hostnames in IP addresses. If you have a DNS server on your network, you can configure your Cisco device to use it for name resolution. Here are the steps:
*(Optional) If you previously disabled DNS searches on your device, re-enable it using the ip domain-lookup command.
*Specify the DNS server IP address using the ip name-server command. Up to six DNS servers can be specified.
*(Optional) Specify the domain name to be added to the host name that you type using the ip domain-name command.
Here is an example of setup:
Floor1 (config) #ip servername 192.168.0.100
In the output above, you can see that I have specified the IP address of my DNS server (192.168.0.100). Let's say the DNS server contains a record of a server called File Sharing. I can try to ping this host using the hostname to verify the name resolution process is working:
Floor 1 # ping file share
Translate "File Sharing" ... domain server (192.168.0.100)
Write the escape sequence for frustration.
Send 5 100 bytes ICMP echoes to 192.168.0.110, timeout 2 seconds:
. !!!!
Pass rate of 80 percent (4/5), round trip minute / average / max = 0/0 / 1ms
As you can see from the above result, the hostname file share has been translated to IP address 192.168.0.110.