The Fast EtherChannel feature can be configured between:
Cisco 7200 series routers, Cisco 7500 series routers, and Cisco 7000 series routers with the Cisco 7000 Series Route Switch Processor (RSP7000) and Cisco 7000 Series Chassis Interface (RSP7000CI).
A Cisco 7500 series router or a Cisco 7000 series router with the RSP7000 and RSP7000CI and a Catalyst 5000 switch.
Fast EtherChannel provides higher bidirectional bandwidth, redundancy, and load sharing. Up to four Fast Ethernet interfaces can be bundled in a port-channel, and the device can support up to four port channels. The Fast EtherChannel feature is capable of load balancing traffic across Fast Ethernet links. Unicast, broadcast, and multicast traffic are distributed across the links providing higher performance and redundant parallel paths. In the event of a link failure, traffic is automatically redirected to other functional links within the Fast EtherChannel.
In the Fast EtherChannel feature, IP traffic is distributed over the port-channel interface, while traffic from other routing protocols is sent over a single link. Bridged traffic is distributed on the basis of the Layer 3 information in the packet. If the Layer 3 information does not exist in the packet, the traffic is sent over the first link.
Fast EtherChannel supports all features currently supported on the Fast Ethernet interface. You must configure these features on the port-channel interface rather than on the individual Fast Ethernet interfaces. Fast EtherChannel connections are fully compatible with Cisco VLAN and routing technologies. The Inter-Switch Link (ISL) VLAN trunking protocol can carry multiple VLANs across a Fast EtherChannel. Devices attached to Fast EtherChannel links can provide full multiprotocol routing with support for host standby using the Hot Standby Router Protocol (HSRP).
The port-channel (consisting of up to four Fast Ethernet interfaces) is treated as a single interface. A port-channel is used in Cisco software to maintain compatibility with existing commands on the Catalyst 5000 switch. You can create the Fast EtherChannel by using the interface port-channel interface configuration command. You can assign up to four Fast Ethernet interfaces to a port-channel by using the channel-group interface configuration command.
Additional Fast EtherChannel features include:
Hot Standby Router Protocol (HSRP)
For more information about configuring HSRP, see the “Configuring IP Services” chapter in the IP Application Services Configuration Guide.
Cisco Express Forwarding (formerly known as CEF) and distributed Cisco Express Forwarding (formerly known as dCEF)
For more information about configuring Cisco Express Forwarding, see the “Configuring Cisco Express Forwarding” module of the IP Switching Configuration Guide.