Instruction manual

893-839-C 4-1
Chapter 4 Operating a Stack of Hubs
This chapter contains relevant information about your BayStack 100-series
hub. The chapter includes information about hub configuration, swapping a hub
in a stack, and using the communications port.
Automatic Hub Configuration
When a 100-series hub experiences a change in cascade connectivity, a reset, or
a power cycle within the stack, it initiates an automatic configuration process.
The process varies, depending on the changes you make, as shown in T
able 4-1.
Table 4-1. BayStack hub configuration process
Hubs affected Type of change and effect
All hubs
in a stack
• When the configuration process begins, all hubs load their previously stored
configuration.
• Changes you make to the segment select switch on the hub rear panel take effect
immediately. If you change the segment select switch when power to the hub is off,
the change takes effect when it is powered on.
• When you swap a hub to a new position in the same stack, it retains its previously
stored configuration regardless of where in the stack it is.
Unmanaged stacks • When you make any changes to an unmanaged stack (add, swap, or reset a hub),
all hubs retain their previously stored configurations. If a hub has no previously
stored configuration, it uses its factory default configuration.
Managed stacks • When you add an NMM to an existing stack, the NMM “learns” the configuration of
each hub in the stack.
• When you reset a hub in a managed stack to its factory default configuration (by
pressing the Reset button for 10 seconds), the NMM stores this new configuration
and discards the previous configuration.
• When you add a hub to a managed stack, the new hub retains its previously stored
configuration and the NMM learns its configuration.
• If you swap an existing hub in a managed stack with a new hub that is not from that
stack, the NMM reconfigures the new hub to assume the configuration of the old
hub within 30 seconds. This feature is called SmartSwap
™
.
If the new hub cannot assume the configuration of the old one (for example, if it is
a different type or has a different number of ports), then the new hub keeps its
previously stored configuration. The NMM stores this configuration and discards the
configuration of the old hub.
893-839-CBook Page 1 Thursday, December 12, 1996 4:18 PM