◦ The IP address of a DNS server available to the switch
◦ The domain suffix of a domain available to the configured DNS serverthen:
◦ A DNS-compatible command that includes the host name of a device in the same domain as the configured
domain suffix can reach that device.
◦ A DNS-compatible command that includes a fully qualified domain name can reach a device in any domain
that is available to the configured DNS server.
Example:
Suppose the switch is configured with the domain suffix
mygroup.
Switch.net
and the IP address for an
accessible DNS server. If an operator wants to use the switch to ping a target host in this domain by using the
DNS name "leader" (assigned by a DNS server to an IP address used in that domain), the operator can use either
of the following commands:
Figure 97: Example: of using either a host name or a fully qualified domain name
In the proceeding Example:, if the DNS server's IP address is configured on the switch, but a domain suffix is
either not configured or is configured for a different domain than the target host, the fully qualified domain name
must
be used.
Note that if the target host is in a domain
other than
the domain configured on the switch:
• The host's domain must be reachable from the switch. This requires that the DNS server for the switch must
be able to communicate with the DNS servers in the path to the domain in which the target host operates.
• The fully qualified domain name must be used, and the domain suffix must correspond to the domain in which
the target host operates, regardless of the domain suffix configured in the switch.
Example:
Suppose the switch is configured with the domain suffix
mygroup.
Switch.net
and the IP address for an
accessible DNS server in this same domain. This time, the operator wants to use the switch to trace the route to a
host named "remote-01" in a different domain named
common.group.net
. Assuming this second domain is
accessible to the DNS server already configured on the switch, a
traceroute
command using the target's fully
qualified DNS name should succeed.
Figure 98: Example: using the fully qualified domain name for an accessible target in another domain
Chapter 13 Troubleshooting
545