Cisco 15327 - Manual (Page 149)

C H A P T E R
10-1
Ethernet Card Software Feature and Configuration Guide, R7.2
10
Configuring Link Aggregation
This chapter describes how to configure link aggregation for the ML-Series cards, both EtherChannel
and packet-over-SONET/SDH (POS) channel. For additional information about the Cisco IOS
commands used in this chapter, refer to the Cisco IOS Command Reference publication.
This chapter contains the following major sections:
• Understanding Link Aggregation, page 10-1
• Understanding Encapsulation over EtherChannel or POS Channel, page 10-7
• Monitoring and Verifying EtherChannel and POS, page 10-9
Understanding Link Aggregation
The ML-Series card offers both EtherChannel and POS channel. Traditionally EtherChannel is a
trunking technology that groups together multiple full-duplex IEEE 802.3 Ethernet interfaces to provide
fault-tolerant high-speed links between switches, routers, and servers. EtherChannel forms a single
higher bandwidth routing or bridging endpoint and was designed primarily for host-to-switch
connectivity. The ML-Series card extends this link aggregation technology to bridged POS interfaces.
POS channel is only supported with LEX encapsulation.
Link aggregation provides the following benefits:
• Logical aggregation of bandwidth
• Load balancing
• Fault tolerance
Port channel is a term for both POS channel and EtherChannel. The port channel interface is treated as
a single logical interface although it consists of multiple interfaces. Each port channel interfaces consists
of one type of interface, either Fast Ethernet, Gigabit Ethernet, or POS. You must perform all port
channel configurations on the port channel (EtherChannel or POS channel) interface rather than on the
individual member Ethernet or POS interfaces. You can create the port channel interface by entering the
interface port-channel interface configuration command.
Port channel connections are fully compatible with IEEE 802.1Q trunking and routing technologies.
IEEE 802.1Q trunking can carry multiple VLANs across a port channel.
Each ML100T-12, ML100X-8, or ML1000-2 card supports one POS channel, a port channel made up of
the two POS ports. A POS channel combines the two POS port capacities into a maximum aggregate
capacity of STS-48c or VC4-16c.