User`s guide

AT-S39 User’s Guide
37
When Does a Switch Need an IP Address?
One of the tasks to building or expanding a network is deciding which of
the managed switches need to be assigned unique IP addresses. The
rule used to be that a managed switch needed an IP address if you
wanted to manage it remotely, such as with the Telnet application
protocol. However, if a network contained a lot of managed switches,
having to assign each one an IP address was often cumbersome and
time consuming. It was also often difficult keeping track of all the IP
addresses.
The enhanced stacking feature of the AT-8000 Series switch simplifies all
this. With enhanced stacking, you need assign an IP address to only one
AT-8000 Series switch in each subnet in your network. The switch with
the IP address is referred to as the Master switch of the subnetwork. All
switches in the same subnet share the IP address.
Starting a local or remote management session on the Master switch
automatically gives you complete management access to all the other
switches in the same subnet.
This feature has two primary benefits. First, it helps reduce the number
of IP addresses you have to assign to your network devices. Second, it
allows you to configure multiple switches through the same local or
remote management session.
If your network consists of multiple subnets, you must assign a unique IP
address to at least one switch in each subnet. The switch with the IP
address will be the Master switch of that subnet.
When you assign a switch an IP address, you must also assign it a subnet
mask. The switch uses the subnet mask to determine which portion of an
IP address represents the network address and which the node address.
You must also assign the switch a gateway address if there is a router
between the switch and the remote management workstation. This
gateway address is the IP address of the router through which the switch
and management station will communicate.
Note
For further information on enhanced stacking, refer to Enhanced
Stacking Overview on page 58.
If you do not plan to remotely manage any of the AT-8000 Series
switches in your network, then you do not need to assign any of them an
IP address. The switches will operate fine without an IP address and you
will still be able to manage them completely using local management
sessions.