Brocade TurboIron 24X Series Configuration Guide - Manual (Page 520)

486 Brocade TurboIron 24X Series Configuration Guide
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Configuring IP parameters – Layer 2 Switches
Configuring Domain Name Server (DNS) resolver
The Domain Name Server (DNS) resolver feature lets you use a host name to perform Telnet, ping,
and traceroute commands. You can also define a DNS domain on a Layer 2 Switch or Layer 3
Switch and thereby recognize all hosts within that domain. After you define a domain name, the
Layer 2 Switch or Layer 3 Switch automatically appends the appropriate domain to the host and
forwards it to the domain name server.
For example, if the domain “newyork.com” is defined on a Layer 2 Switch or Layer 3 Switch and you
want to initiate a ping to host “NYC01” on that domain, you need to reference only the host name in
the command instead of the host name and its domain name. For example, you could enter either
of the following commands to initiate the ping.
TurboIron#ping nyc01
TurboIron#ping nyc01.newyork.com
Defining a DNS entry
You can define up to four DNS servers for each DNS entry. The first entry serves as the primary
default address. If a query to the primary address fails to be resolved after three attempts, the next
gateway address is queried (also up to three times). This process continues for each defined
gateway address until the query is resolved. The order in which the default gateway addresses are
polled is the same as the order in which you enter them.
Suppose you want to define the domain name of newyork.com on a Layer 2 Switch and then define
four possible default DNS gateway addresses. To do so, enter the following commands.
TurboIron(config)#ip dns domain-name newyork.com
TurboIron(config)#ip dns server-address 10.157.22.199 10.96.7.15 10.95.7.25
10.98.7.15
Syntax: ip dns server-address <ip-addr> [<ip-addr>] [<ip-addr>] [<ip-addr>]
In this example, the first IP address in the ip dns server-address... command becomes the primary
gateway address and all others are secondary addresses. Because IP address 10.98.7.15 is the
last address listed, it is also the last address consulted to resolve a query.
Using a DNS name To initiate a trace route
Example
Suppose you want to trace the route from a Layer 2 Switch to a remote server identified as NYC02
on domain newyork.com. Because the newyork.com domain is already defined on the Layer 2
Switch, you need to enter only the host name, NYC02, as noted below.
TurboIron#traceroute nyc02
Syntax: traceroute <host-ip-addr> [maxttl <value>] [minttl <value>] [numeric] [timeout <value>]
[source-ip <ip addr>]
The only required parameter is the IP address of the host at the other end of the route.
After you enter the command, a message indicating that the DNS query is in process and the
current gateway address (IP address of the domain name server) being queried appear on the
screen.