Cisco 10000 - Manual (Page 463)

C H A P T E R
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Cisco 10000 Series Router Software Configuration Guide
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20
Configuring Gigabit EtherChannel Features
On a Cisco 10000 Series router, a Gigabit EtherChannel (GEC) is a specialized interface type comprising
aggregated Gigabit Ethernet links. A GEC bundle is synonymous with port channel and can have a
minimum of one or a maximum of 8 active links. The bandwidth of the GEC interface is the aggregate
of all the physical member links comprising the GEC bundle.
Note Cisco IOS Release 12.2(31)SB supports a maximum of 4 member links per GEC bundle. In Cisco IOS
Release12.2(15)BX, the maximum number of links per GEC bundle has been increased from 4 to 8.
The Gigabit EtherChannel can be deployed in two ways on the Cisco 10000 Series router:
• Core facing or network facing deployment is an uplink EtherChannel that connects the
Cisco 10000 Series router to the service provider. This setup has multiple physicals links bundled
per GEC interface and allows:
– Load balancing across all the active interfaces.
– Combination of different Gigabit Ethernet (GE) ports ( both shared port adaptors and line cards)
• Access facing or subscriber facing deployment connects the Cisco 10000 Series router to the
subscriber edge. This setup typically has only one active member link on a GEC bundle interface.
The remaining links in the GEC bundle serve as passive links. Traffic is sent only through the active
member link, while the passive link is used as a backup when the active member link fails. This
arrangement provides link redundancy with no loss of Point-to-Point Protocol over Ethernet
(PPPoE) sessions during link failover.
– Load balancing is not applicable when there is only one active link in a GEC bundle.
– Queuing action is allowed only on the GEC bundle and not on member links.
Note A GEC bundle can include a combination of active and passive links. In an M:N mode, ‘M’
denotes active links and ‘N’ denotes passive links. In a 1:N mode only one link is active per
GEC bundle and ‘N’ denotes passive links. Passive links operate as backup links but do not
transfer any network traffic.
This chapter describes Gigabit EtherChannel (GEC) enhancements implemented on the
Cisco 10000 Series routers and includes the following topics:
• Feature History for Gigabit EtherChannel, page 20-2
• Prerequisites for Gigabit EtherChannel Configuration, page 20-3
• Restrictions for Gigabit EtherChannel Configuration, page 20-3