Management and Configuration Guide K/KA/KB.15.15

DNS resolver operation
• When the switch is configured with only the IP address of a DNS server available to the switch,
a DNS-compatible command, executed with a fully qualified domain name, can reach a
device found in any domain accessible through the configured DNS server.
• When the switch is configured with both of the following:
The IP address of a DNS server available to the switch•
• The domain suffix of a domain available to the configured DNS server
then:
• 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.HP 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 237 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.HP 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.
DNS resolver 445