Datasheet

Caution: GBICs are sensitive to power spikes. It is advised to regulate the power to the devices to
avoid GBIC failures.
Cascaded Stack Connections with a Redundant Link
Cascaded stack configuration with a redundant link consists of one GigaStack GBIC per switch. Multiple
connections exist between these modules. By using one module per switch, you are able to interconnect
between three and nine switches using only one GigaStack module per switch. The cable is daisy chained
between switches by connecting opposite port numbers between switches. Port 1 to neighboring switch port 2
and so on. Physical redundancy occurs when you complete the connection between the first and last switch.
Every port in all GigaStack modules will have a connection in use.
In this configuration, all GigaStack interfaces will automatically negotiate to half−duplex. All GigaStack ports
will act as a repeater and share the one Gbps channel. A loop configuration will be detected by a loop
detection algorithm and one of the links on a GigaStack module will be used as the redundant link. The
redundant link in the stack is disabled for data transmission while all other links in the stack are up. When
another link in the stack goes down, the redundant link will be enabled for data transmission. No user
intervention is required.
Note: This configuration is only supported if all switches in the stack run software that supports the loop
detection mechanism.
Using the Cross−Tack Uplink Fast Feature
Cross−stack UplinkFast (CSUF) provides a fast spanning−tree transition (fast convergence in less than one
second under normal network conditions) across a stack of switches that use the GigaStack GBICs connected
Cisco − Catalyst Switch GigaStack Configuration and Implications