HP Cisco Catalyst Blade Switch 3020 Cisco Catalyst Blade Switch 3020 for HP So - Page 214

Understanding Interface Types Chapter 8 Configuring Interface Characteristics EtherChannel Port Groups EtherChannel port groups treat multiple switch ports as one switch port. These port groups act as a single logical port for high-bandwidth connections between switches or between switches and servers. An EtherChannel balances the traffic load across the links in the channel. If a link within the EtherChannel fails, traffic previously carried over the failed link changes to the remaining links. You can group multiple trunk ports into one logical trunk port or multiple access ports into one logical access port. Most protocols operate over either single ports or aggregated switch ports and do not recognize the physical ports within the port group. Exceptions are the DTP, the Cisco Discovery Protocol (CDP), and the Port Aggregation Protocol (PAgP), which operate only on physical ports. When you configure an EtherChannel, you create a port-channel logical interface and assign an interface to the EtherChannel. se the channel-group interface configuration command to dynamically create the port-channel logical interface. This command binds the physical and logical ports together. For more information, see Chapter 28, "Configuring EtherChannels and Layer 2 Trunk Failover." Dual-Purpose Uplink Ports The Cisco Catalyst Blade Switch 3020 supports dual-purpose uplink ports on six of the eight uplink ports. Four of the uplink ports, 17 to 20, are considered as a single interface with dual front ends (an RJ-45 connector and an SFP module connector). The dual front ends on ports 17 to 20 are not redundant interfaces, and the switch activates only one connector of the pair. By default, the switch dynamically selects the interface type that first links up. However, you can use the media-type interface configuration command to manually select the RJ-45 connector or the SFP module connector. For information about configuring speed and duplex settings for a dual-purpose uplink, see the "Setting the Type of a Dual-Purpose Uplink Port" section on page 8-12. Uplink ports 17 to 20 have two LEDs: one shows the status of the RJ-45 port, and one shows the status of the SFP module port. The port LED is on for whichever connector is active. For more information about the LEDs, see the hardware installation guide. Ports 23x and 24x are different from the other dual-purpose ports. When operating in external mode, these ports are single, uplink 10/100/1000BASE-T copper Gigabit Ethernet ports. When operating in internal mode, they use the 1000BASE-X mode, and they form a cross-connection with a switch that is installed in a corresponding module bay in the blade server. The default operation mode for ports 23x and 24x is external, set by using the rj45 keyword of the media-type interface configuration command. Cisco Catalyst Blade Switch 3020 for HP Software Configuration Guide 8-4 OL-8915-01