CCNA Complete Guide 2nd Edition.pdf - Cisco Learning Home

Chapter 10
Managing a Cisco Internetwork
Resolving Hostnames
- By properly setting up hostname resolution or translation service, a hostname instead of an IP
address can be used to communicate with a device.
- Below lists the 2 available methods used to resolve hostnames to IP addresses:
i) Build a host table on each device (static host table).
ii) Setup a Domain Name System (DNS) server (dynamic host table).
- Below lists some Cisco IOS IP naming services commands:
ip domain-name {name} Defines the default domain name of a device.
Global configuration command.
ip domain-lookup Tells the IOS to resolve unknown hostnames and wrongly typed
commands using DNS. Global configuration command.
ip name-server {svr1}
[svr2… svr6]
Configures the DNS name server IP addresses (max of 6).
Global configuration command.
ip host {name} {ip-addr} Creates a static entry in the host table.
Global configuration command.
no ip host {name} Removes a static entry from the host table.
Global configuration command.
show hosts Lists DNS and host table information. EXEC command.
Switch#conf t
Switch(config)#ip host router01 192.168.0.1
Switch(config)#ip host router02 192.168.0.2
Switch(config)#ip name-server 172.16.0.1 172.16.0.2
Switch(config)#^Z
Switch#
Switch#sh hosts
Default domain is not set
Name/address lookup uses domain service
Name servers are 172.16.0.3, 172.16.1.3
Codes: u - unknown, e - expired, * - OK, ? - revalidate
t - temporary, p - permanent
Host Port Flags Age Type Address(es)
router01 None (perm, OK) 0 IP 192.168.0.1
router02 None (perm, OK) 0 IP 192.168.0.2
Switch#
Note: The perm in the Flags column represents a manually configured entry; while the temp
represents a cached DNS-resolved entry.
- It is recommended to have at least 2 name servers for redundancy and availability purposes.
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Copyright © 2008 Yap Chin Hoong
yapchinhoong@hotmail.com