Map hostnames to IP addresses

It is possible to define static hostname-to-address mappings on a Cisco device for the purpose of name resolution. This is usually done in environments without a DNS server.

The mappings can be defined using the global configuration command ip host HOSTNAME IP_ADDRESS:

Floor1(config)#ip host HQ_SERVER 192.168.0.100

In the output above we’ve defined the IP address of 192.168.0.100 for the hostname HQ_SERVER. To display the hostname-to-address mappings, the show hosts command is used:

Floor1#show hosts
Default Domain is not set
Name/address lookup uses domain service
Name servers are 255.255.255.255

Codes: UN - unknown, EX - expired, OK - OK, ?? - revalidate
temp - temporary, perm - permanent
NA - Not Applicable None - Not defined

Host Port Flags Age Type Address(es)
HQ_SERVER None (perm, OK) 0 IP 192.168.0.100

We can ping the server using its hostname to verify that the hostnames are being resolved:

Floor1#ping HQ_SERVER

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.0.100, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 0/0/1 ms

You can see that HQ_SERVER responded to the ping request, which means that the name resolution was successful.

NOTE
The drawback of this method of name resolution is that we need to create static hostname-to-address mappings on each device in order to be able to resolve hostnames. If possible, use DNS instead.
upravnik