Storage Area Networks For Dummies®

164
Par t II: Designing and Building a SAN
Notice the naming convention that I use. The switch’s name is Switch-x,
where x is replaced with the fabric that it belongs to, followed by its switch
number within the fabric (1, 2, 3, and so on). Note that the IP address just
so happens to follow the domain ID. This isn’t part of any naming convention;
it just worked out this way for this example. The domain ID needs to
be a number between 1 and 255. If you set it to 0 (zero) on most switches, it
will automatically be set to something unique if it joins another fabric (gets
plugged into another switch). But for your first-time SAN, just set it yourself.
I made all domain IDs unique even though they’re in different fabrics because
if you decide in the future to connect this SAN fabric with the other one and
expand with more switches, the two fabrics will be easier to merge with each
other if they have unique domain IDs between them. (But that’s a whole other
story . . . perhaps Advanced SANs For Dummies . . . hmmm.)
Configuring the switches
Most switch vendors give you a way to set the TCP/IP address through the
front display on the switch. You press the appropriate buttons to navigate
though the menu until you find the IP address settings and cycle through the
numbers. It’s just like setting the clock on your VCR. Can’t do that either, eh?
Well, if that doesn’t work or the switch doesn’t have a display on the front,
here’s another way.
A default IP address is usually assigned to the switch from the factory —
something that no one else uses, such as 1.1.1.1 or something similar. To
communicate with the switch and change settings, you need to take a laptop
or PC and set its IP address to 1.1.1.2 or something close so that it can talk IP
to the switch. Connect a network cable between the laptop and the switch,
either directly via an Ethernet crossover cable or through a hub. Use the
telnet program from the computer to the switch, and you’ll be able to log in
to the switch’s interface to make the necessary changes. Figure 7-3 shows the
connection to the switch from a PC or laptop using a telnet command.
C:\> telnet 1.1.1.1
opening 1.1.1.1...
Figure 7-3:
Configuring
the switch
over the
network,
using a
telnet
command
from a PC or
laptop.
SwitchOS login:
Server or laptop
TCP/IP set to 1.1.1.2
Setting the Switch IP Address
Ethernet cable
directly connected
Switch with default
TCP/IP address = 1.1.1.1