Routers can use a DNS server, or you can build a Host table which allows lookups between IP addresses and host names. Once this table is created, you can ping or Telnet using the Host name instead of the IP address. In the confguration mode :
ip host name ip_address
For example: ip host Chicago1 172.16.20.2
ip host LA1 174.28.19.5
*** different than the “hostname” command, which just applies a name to the router being accessed
view the host table: show hosts