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.
Cisco IOS Release 12.2(31)SB supports a maximum of 4 member links per GEC bundle. In Cisco IOS
Note
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
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Cisco 10000 Series router to the service provider. This setup has multiple physicals links bundled
per GEC interface and allows:
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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.
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Note
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 23-2
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Prerequisites for Gigabit EtherChannel Configuration, page 23-3
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Restrictions for Gigabit EtherChannel Configuration, page 23-3
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Load balancing across all the active interfaces.
Combination of different Gigabit Ethernet (GE) ports ( both shared port adaptors and line cards)
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.
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.
C H A P T E R
Cisco 10000 Series Router Software Configuration Guide
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